My ZX81 was the only computer my dad could buy me for the couple of West Marks we had. Completely sufficient for me to learn programming in BASIC and when I got too frustrated of that beeing too slow dive into Machine Code programming. Enough for me to study Math and "Information processing" - as they called computer scienses back then and chose a carreer in computing. A contemporary version of the ZX81 is the Raspberry PI (also originally from the UK)
As i learned more how PC (and MSDOS, BIOS) worked, i had crazy idea to do some multitasking OS for my ZX81 but i have no access to materials/books in my country (and small town) [finally i dissambled ROM to notebook using small dissambler from book on Z80), but without schematic i couldn't understand why interrupt routine is so strange and couldn't replace it with my own then, so didn't make it finally. But i done Excel or rather QuatroPro "clone", when was possible to use formulas written with BASIC functions (exploiting evaluator found in ROM) and even "draw charts".
Oh, that's a cool project. You should share your old code, if you still have it. There's a pretty big ZX81 community, and I'm sure some people would pick that project up and run with it.
@@8BitRetroJournal I'm afraid that only copies are on cassettes and even ignoring that i have only bleak idea were they should be, it is possible that they are unreadable after 30 years without rewind ☹
I'd say send them to the video uploader, and see what happens. I have a way to read and upload cassette files, and have many of the programs saved to ".p" and ".z81" files for a number of emulators. I've got a nicely varied collection, I should say, and most of that can be found online rather easily. :)
@@kumbah2006 When I did a reclamation of some cassette's that came with an eBay buy, there were two categories of programs: 1) homebrew ones, and 2) commercial. I had trouble recovering the commercial (ZX81 Flight Simulator) but was able to find a copy online.
I had a Timex Sinclair 1000 which was the American version and it was a rather powerful machine with limitations like the horrible keyboard and long tape loading. Very affordable though.
If you still have one, you can get something called a ZXpand (not 100% sure of the spelling), that will put an end to long tape loading times, and open up a world of shared "tapes" and files, spread all over the internet by us Timex "nuts". I'm now mostly focusing on the emulators, but once I find a new place to restart my "lab", I'll be doing a few videos on a similar machine, or using the emulator in real time. I have some content already uploaded, and it's available to view, done up a few years ago. The emulator I use most (these days) is called "Eighty-One" and is quite easy to find, and it's free, so to re-visit the Timex world, you only need to get that and a copy of the "manual", which I should find a way to share online. I also should package up a few of the programs I wrote and put them out there in that same place as the "booklet". Take care ! :)
There was an MS-DOS version for Z80, the MSX dos. I guess that no one ported it to ZX81 or Spectrum just because Spectrum did not had a wide spread floppy users and software and it was mostly used for games. However, I saw CP/M running on an modded Spectrum with a custom floppy interface and an 8" floppy. Just for the sake of it, how would have looked the PC with Z80 CPU instead I8088? 10 PRINT "Happy holydays and Merry Christmas!" 20 GOTO 10 RUN
I did look for an MS-DOS version for a Z80 so thank you for pointing me in that direction. I'll have to take a look at it. Happy Holidays to you as well!
@@craigtheduck Right, but it's still Z80 so that's a nice start. The difference is how it integrates into a system (that 20% of 80/20 that the biggest hurdle).
Great video :) The IBM PC had the advantage of having off-the-shelf components and the BIOS being cracked very quickly, so production started with multiple companies. The ZX81, like other 8-bit computers from that time, were in-house systems each a bit different from another. Cheers!
Nice project! MS-DOS is a shortcut and heavily modified version CP/M. Even MSX-DOS has a big core coming from CP/M. Amstrad OS the same. Despite the CP/M they don't have any external floppy disk descriptor and they use the internal FAT structure.
Love the video, but I have a suggestion: Please get an external microphone (so you can sound clearer and more distinct), or - even better - you should record the audio on a tape machine or voice recorder, then edit that into the video. You are not clearly audible to me. (I know my headphones aren't the greatest, but I can hear most videos on YT. The sound on your video seems a bit muffled, but it could just be me.) Awesome content, and it's fun seeing that little machine, like the two I have stored away, actually running something akin to a DOS system. :) Great job ! Now, where can I download that? I'm serious. :)
On a few of my videos the mic wasn't working as it got turned off and so reverted to my phone's mic, making it sound echoey. I film ahead a handful of videos and then rearrange them so there may be one or two in the future where the audio gets a bit worse again. I did catch it in time to try and fix the audio in audacity as best as I could but obviously, if the source is echoing, it's hard to clean it up fully.
ZX81 (and its predecessor ZX80) were the only home computers without ASCII, not even bastardized watered-down ASCII like the PET had. The character codes on the ZX81 were not in any way related to ASCII, it was a completely separate character set. Some of the chars missing were exclamation mark, apostrophe and semicolon. # and @ were also notoriously absent.
[shrug] At least the alphabetic characters were in a contiguous block, unlike in EBCDIC (typically found on IBM mainframe and minicomputer) where you saw the alphabet being broken up into blocks with some control characters interspersed (which may not seem to make sense until you look at the code values in hexadecimal, and notice the pattern -- the character coding is based around binary-coded decimal and that the control codes occupy parts where the nibbles were outside the 0-9 range).
The TS-1000 (maybe the Zeddy?) has a semicolon - it's on the "X" key - as a shifted character while in L mode. My emulator reproduces a semicolon just fine. Perhaps check your zeddy's membrane keys, and see if I'm right? We definitely don't have the # sign, or an "!" on the TS-1000 - that's for sure! I think the TS-2068 has all of those characters, as I still own one. :) (Also have several emulators that all reproduce what I've described.)
The motherboard of the PC does not have any video output. You needed to add either an MDA (Monochrome Display Adapter) or a CGA (Color Graphics Adapter). The original ones were big fully populated boards too.
@@8BitRetroJournal If you bought an IBM PC computer, you always got one of the available video cards, so it was included in the price of the machine. Disk controller + floppy drives were 'technically' optional, but very few people would buy that machine to just use it with cassettes.
@@8BitRetroJournal the basic IBM PC came with 16K of RAM and no floppy disks. It did however have a vastly better keyboard and, because the CPU wasn’t used to generate video, ran much faster.
@@stevetodd7383 Yup, and the CPU was also slightly better, though in the greater scheme of things that's not saying too much. If you follow my channel, I'll have a video in a couple of weeks were I unbox a US ZX81 and it has a mod on the side of a 15-pin connector that presumably connected to an external keyboard. Also, as a kid I built my own keyboard out of switches -- I think I mounted them on a piece of cardboard and wired them by hand and took a magazine ad of the ZX81 and cut out the keycaps, pasted them on the keys and added clear nail polish to protect them...you can watch a video of it that I did on August 6, 2021.
@@8BitRetroJournal I had a MK14 (the machine that Sinclair came up with BEFORE the ZX80, which had an awful hex keypad (spring steel domes under a plastic membrane). Likewise I bodged it to use a desktop calculator keyboard with legends on Typex.
I think I still have a bunch of old cards as well - gee, I'll be busy as a beaver once I get settled into a new place - sorting and maybe doing videos of what I have to share or give away.
Haha, I did this in the late 80's as a kid, Me and my friend thought we were the "S-H-I-T" (we were 9yo kids, wadda ya want? LOL) on a Commodore 64c, we made a BASIC Prompt that we could do the same, Type in "DIR or a DOS command and Fake it till ya Make It" ... DOS is alot more complex that just "Boom, DOS"... It could be done tho, in ROM, th problem was that ROM was SO expensive back then, now... not so much (and sometimes also very expensive still... because "Reasons?") - there were Custom ROM chips back then, but DAMN it was almost Impossible to get them and they were Expensive and a pin in the Butt to get working on system's with such Limited RAM and Address Space, They were really great tho, we had a ton of fun on these things...
The RAM Disk OS is pretty interesting but you need hardware to run it on a real machine. But year, writing that simple command interpreter was fun. I could see a company trying to sell you PCs making this little program in the 80s for all sorts of platforms and giving it away free to get you to upgrade...I guess the distribution back then would have been the problem since there was no word wide web.
I'm actually writing a DOS "simulator" in BASIC, but it's pretty lousy at the moment. :) Barely works, but it makes use of commands found on Extender, an MS-DOS based emulator by Carlo Delhez. Probably won't work on the real machine without a ZXpand unit. Might want to get me one of those things ! :) I think the "Eighty-One" emulator has a ZXpand "mode" built in, but am not sure. (Pretty sure I saw that in the list of "hardware" supported.) Okay, I checked, and YES, it has ZXpand + support. Not sure what the + is all about, but am guessing expanded RAM, ZonX sound, and SD card support. Joystick? Hmmm ... Dang, now I know I "need" one of those for the real hardware! :)
the first minute of the video quickly gave the answer : no the little machine was not as capable as the one costing 10 times more... the horrible typing on the dysfunctional keyboard already settles it.
Well, I wasn't talking about form here, but function. There were a ton of keyboards out there you could buy for pretty inexpensive. In fact, if you watch one of my videos (April 7, 2021) I made my own. The whole point here is that this stripped down machine had similar power, it just lacked all the stuff the PC had but then again, only cost $99.
@@8BitRetroJournal I do recall seeing an article in a magazine (I don't recall which one) that outlined how one could modify a TI-99 keyboard to use with the Sinclair ZX-81. The keyboard was relatively easy to obtain since Radio Shack had carried them for a while. The modification involved cutting some traces on the board and adding some bodge wires to reconfigure the keyboard matrix (the matrix was quite similar).
@@8BitRetroJournalWell, why don't you do a comparison and demo with one of those magical keyboards then? Your demo is like showing off Windows 95's GUI capabilities, but having no mouse connected, and having to navigate with keyboard shortcuts, then starting to act annoyed like a little child when somebody mentions it.
@@der.Schtefan I'm not quite catching your interpretation of my comment as "then starting to act annoyed." I pointed out there were several keyboards out there but that I wasn't trying to intimate that the ZX81 was comparable to an IBM PC, just that, as toy-like as it seemed, it had some things in common with the IBM PC where it could run MS-DOS (or similar) but was just extremely trimmed down and therefore less expensive. Also, there were people that did expand the machine after having invested in it with keyboard, disk drives, etc...
@@8BitRetroJournal - I was one of those people who modded the TS-1000 to have more RAM, a physical keyboard (TI 99/4A) and the case to go with it. :) Even managed to mod the video to use inverse video. It worked for quite some time, and then I kind of "lost" the machine. ( - or I gave it away, which wasn't that smart !)
I wrote the shell and I integrated a coupe of programs that I recently had recovered off of some tapes that weren't mine (see my November 9th video on the process I used for that tape recovery). The shooter game was one of them and it was just the right feel to have me include it. (i.e. it could just as well be an MS-DOS game).
@@8BitRetroJournalso, you didn't play a game you typed in? Not even once? Just copied it into your program without knowing if it even works, or playable?
@@nneeerrrd Oh no, I ran it to see what it looked like, but I didn't try to play it so I really didn't understand how it worked -- I mean I got that you shot at things, but did you shoot an any or only the latest, etc... stuff like that.
@@nneeerrrd again, I didn't play it. After first recovering it from tape, I hit RUN and saw it create the screen and kind of watched without hitting any keys., and didn't really pay close attention as I was just wondering if I recoverd it fully or if it would crash Then, when I actually played it during the video, I wasn't quite sure 100% how it worked but it was pretty easy to figure out. So I had run it previously but not played it, i.e. like watching someone play chess versus playing chess yourself.
There were several places where I corrected it with a comment, but yes, i was spelling it out in my mind phonetically...my research area is automatic speech recognition so I spend too much time with phonetic dictionaries.
My ZX81 was the only computer my dad could buy me for the couple of West Marks we had. Completely sufficient for me to learn programming in BASIC and when I got too frustrated of that beeing too slow dive into Machine Code programming. Enough for me to study Math and "Information processing" - as they called computer scienses back then and chose a carreer in computing. A contemporary version of the ZX81 is the Raspberry PI (also originally from the UK)
This is some ancient retro when one realizes that 'MSDOS' is 'Micro Sinclair DOS' and not 'Micro Soft DOS'.
As i learned more how PC (and MSDOS, BIOS) worked, i had crazy idea to do some multitasking OS for my ZX81 but i have no access to materials/books in my country (and small town) [finally i dissambled ROM to notebook using small dissambler from book on Z80), but without schematic i couldn't understand why interrupt routine is so strange and couldn't replace it with my own then,
so didn't make it finally.
But i done Excel or rather QuatroPro "clone", when was possible to use formulas written with BASIC functions (exploiting evaluator found in ROM) and even "draw charts".
Oh, that's a cool project. You should share your old code, if you still have it. There's a pretty big ZX81 community, and I'm sure some people would pick that project up and run with it.
@@8BitRetroJournal I'm afraid that only copies are on cassettes and even ignoring that i have only bleak idea were they should be, it is possible that they are unreadable after 30 years without rewind ☹
@@AK-vx4dy If you find them, contact me and I'll try and recover the info for you. Have had success with that.
I'd say send them to the video uploader, and see what happens.
I have a way to read and upload cassette files, and have many of the programs saved to ".p" and ".z81" files for a number of emulators.
I've got a nicely varied collection, I should say, and most of that can be found online rather easily. :)
@@kumbah2006 When I did a reclamation of some cassette's that came with an eBay buy, there were two categories of programs: 1) homebrew ones, and 2) commercial. I had trouble recovering the commercial (ZX81 Flight Simulator) but was able to find a copy online.
That's superb work, and a clever bit of BASIC trickery! Lovely to see behind the curtain at the end.
I had a Timex Sinclair 1000 which was the American version and it was a rather powerful machine with limitations like the horrible keyboard and long tape loading. Very affordable though.
If you still have one, you can get something called a ZXpand (not 100% sure of the spelling), that will put an end to long tape loading times, and open up a world of shared "tapes" and files, spread all over the internet by us Timex "nuts".
I'm now mostly focusing on the emulators, but once I find a new place to restart my "lab", I'll be doing a few videos on a similar machine, or using the emulator in real time. I have some content already uploaded, and it's available to view, done up a few years ago.
The emulator I use most (these days) is called "Eighty-One" and is quite easy to find, and it's free, so to re-visit the Timex world, you only need to get that and a copy of the "manual", which I should find a way to share online. I also should package up a few of the programs I wrote and put them out there in that same place as the "booklet". Take care ! :)
WOW that was awesome, thanks for making that video...be sure to copy that up to some retro site...
There was an MS-DOS version for Z80, the MSX dos. I guess that no one ported it to ZX81 or Spectrum just because Spectrum did not had a wide spread floppy users and software and it was mostly used for games. However, I saw CP/M running on an modded Spectrum with a custom floppy interface and an 8" floppy.
Just for the sake of it, how would have looked the PC with Z80 CPU instead I8088?
10 PRINT "Happy holydays and Merry Christmas!"
20 GOTO 10
RUN
I did look for an MS-DOS version for a Z80 so thank you for pointing me in that direction. I'll have to take a look at it. Happy Holidays to you as well!
MSX is almost a completely different computer architecture from the Sinclair family of micros, despite using the same basic CPU instruction set.
@@craigtheduck Right, but it's still Z80 so that's a nice start. The difference is how it integrates into a system (that 20% of 80/20 that the biggest hurdle).
Great video :) The IBM PC had the advantage of having off-the-shelf components and the BIOS being cracked very quickly, so production started with multiple companies. The ZX81, like other 8-bit computers from that time, were in-house systems each a bit different from another. Cheers!
Nice project! MS-DOS is a shortcut and heavily modified version CP/M. Even MSX-DOS has a big core coming from CP/M. Amstrad OS the same.
Despite the CP/M they don't have any external floppy disk descriptor and they use the internal FAT structure.
Love the video, but I have a suggestion:
Please get an external microphone (so you can sound clearer and more distinct), or - even better - you should record the audio on a tape machine or voice recorder, then edit that
into the video. You are not clearly audible to me.
(I know my headphones aren't the greatest, but I can hear most videos on YT.
The sound on your video seems a bit muffled, but it could just be me.)
Awesome content, and it's fun seeing that little machine, like the two I have
stored away, actually running something akin to a DOS system. :)
Great job !
Now, where can I download that? I'm serious. :)
On a few of my videos the mic wasn't working as it got turned off and so reverted to my phone's mic, making it sound echoey. I film ahead a handful of videos and then rearrange them so there may be one or two in the future where the audio gets a bit worse again. I did catch it in time to try and fix the audio in audacity as best as I could but obviously, if the source is echoing, it's hard to clean it up fully.
ZX81 (and its predecessor ZX80) were the only home computers without ASCII, not even bastardized watered-down ASCII like the PET had. The character codes on the ZX81 were not in any way related to ASCII, it was a completely separate character set. Some of the chars missing were exclamation mark, apostrophe and semicolon. # and @ were also notoriously absent.
[shrug] At least the alphabetic characters were in a contiguous block, unlike in EBCDIC (typically found on IBM mainframe and minicomputer) where you saw the alphabet being broken up into blocks with some control characters interspersed (which may not seem to make sense until you look at the code values in hexadecimal, and notice the pattern -- the character coding is based around binary-coded decimal and that the control codes occupy parts where the nibbles were outside the 0-9 range).
The TS-1000 (maybe the Zeddy?) has a semicolon - it's on the "X" key - as a
shifted character while in L mode. My emulator reproduces a semicolon just fine.
Perhaps check your zeddy's membrane keys, and see if I'm right?
We definitely don't have the # sign, or an "!" on the TS-1000 - that's for sure!
I think the TS-2068 has all of those characters, as I still own one. :)
(Also have several emulators that all reproduce what I've described.)
The motherboard of the PC does not have any video output. You needed to add either an MDA (Monochrome Display Adapter) or a CGA (Color Graphics Adapter). The original ones were big fully populated boards too.
Right, you need video card. Was that included in the original's selling price?
@@8BitRetroJournal If you bought an IBM PC computer, you always got one of the available video cards, so it was included in the price of the machine. Disk controller + floppy drives were 'technically' optional, but very few people would buy that machine to just use it with cassettes.
@@8BitRetroJournal the basic IBM PC came with 16K of RAM and no floppy disks. It did however have a vastly better keyboard and, because the CPU wasn’t used to generate video, ran much faster.
@@stevetodd7383 Yup, and the CPU was also slightly better, though in the greater scheme of things that's not saying too much. If you follow my channel, I'll have a video in a couple of weeks were I unbox a US ZX81 and it has a mod on the side of a 15-pin connector that presumably connected to an external keyboard. Also, as a kid I built my own keyboard out of switches -- I think I mounted them on a piece of cardboard and wired them by hand and took a magazine ad of the ZX81 and cut out the keycaps, pasted them on the keys and added clear nail polish to protect them...you can watch a video of it that I did on August 6, 2021.
@@8BitRetroJournal I had a MK14 (the machine that Sinclair came up with BEFORE the ZX80, which had an awful hex keypad (spring steel domes under a plastic membrane). Likewise I bodged it to use a desktop calculator keyboard with legends on Typex.
I am really interested in those stacks of "cards", Please do a whole video on those expansion items!
I think I still have a bunch of old cards as well - gee, I'll be busy as a beaver once I get settled into a new place - sorting and maybe doing videos of what I have to share or give away.
@@kumbah2006 If you have any of those stackable cards, i would be interested.
Haha, I did this in the late 80's as a kid, Me and my friend thought we were the "S-H-I-T" (we were 9yo kids, wadda ya want? LOL) on a Commodore 64c, we made a BASIC Prompt that we could do the same, Type in "DIR or a DOS command and Fake it till ya Make It" ... DOS is alot more complex that just "Boom, DOS"... It could be done tho, in ROM, th problem was that ROM was SO expensive back then, now... not so much (and sometimes also very expensive still... because "Reasons?") - there were Custom ROM chips back then, but DAMN it was almost Impossible to get them and they were Expensive and a pin in the Butt to get working on system's with such Limited RAM and Address Space, They were really great tho, we had a ton of fun on these things...
The RAM Disk OS is pretty interesting but you need hardware to run it on a real machine. But year, writing that simple command interpreter was fun. I could see a company trying to sell you PCs making this little program in the 80s for all sorts of platforms and giving it away free to get you to upgrade...I guess the distribution back then would have been the problem since there was no word wide web.
I'm actually writing a DOS "simulator" in BASIC, but it's pretty lousy at the moment. :)
Barely works, but it makes use of commands found on Extender, an MS-DOS based
emulator by Carlo Delhez. Probably won't work on the real machine without a
ZXpand unit. Might want to get me one of those things ! :)
I think the "Eighty-One" emulator has a ZXpand "mode" built in, but am not sure.
(Pretty sure I saw that in the list of "hardware" supported.)
Okay, I checked, and YES, it has ZXpand + support. Not sure what the + is all about, but
am guessing expanded RAM, ZonX sound, and SD card support. Joystick? Hmmm ...
Dang, now I know I "need" one of those for the real hardware! :)
@@kumbah2006 That's cool. Excited to see it once it is complete.
the first minute of the video quickly gave the answer : no the little machine was not as capable as the one costing 10 times more... the horrible typing on the dysfunctional keyboard already settles it.
Well, I wasn't talking about form here, but function. There were a ton of keyboards out there you could buy for pretty inexpensive. In fact, if you watch one of my videos (April 7, 2021) I made my own. The whole point here is that this stripped down machine had similar power, it just lacked all the stuff the PC had but then again, only cost $99.
@@8BitRetroJournal I do recall seeing an article in a magazine (I don't recall which one) that outlined how one could modify a TI-99 keyboard to use with the Sinclair ZX-81. The keyboard was relatively easy to obtain since Radio Shack had carried them for a while. The modification involved cutting some traces on the board and adding some bodge wires to reconfigure the keyboard matrix (the matrix was quite similar).
@@8BitRetroJournalWell, why don't you do a comparison and demo with one of those magical keyboards then? Your demo is like showing off Windows 95's GUI capabilities, but having no mouse connected, and having to navigate with keyboard shortcuts, then starting to act annoyed like a little child when somebody mentions it.
@@der.Schtefan I'm not quite catching your interpretation of my comment as "then starting to act annoyed." I pointed out there were several keyboards out there but that I wasn't trying to intimate that the ZX81 was comparable to an IBM PC, just that, as toy-like as it seemed, it had some things in common with the IBM PC where it could run MS-DOS (or similar) but was just extremely trimmed down and therefore less expensive. Also, there were people that did expand the machine after having invested in it with keyboard, disk drives, etc...
@@8BitRetroJournal - I was one of those people who modded the TS-1000 to have more RAM, a physical keyboard (TI 99/4A) and the case to go with it. :)
Even managed to mod the video to use inverse video.
It worked for quite some time, and then I kind of "lost" the machine.
( - or I gave it away, which wasn't that smart !)
You said you wrote this program. And you said you didn't play the built-in shooter.exe game. How's that possible?
I wrote the shell and I integrated a coupe of programs that I recently had recovered off of some tapes that weren't mine (see my November 9th video on the process I used for that tape recovery). The shooter game was one of them and it was just the right feel to have me include it. (i.e. it could just as well be an MS-DOS game).
@@8BitRetroJournalso, you didn't play a game you typed in? Not even once? Just copied it into your program without knowing if it even works, or playable?
@@nneeerrrd Oh no, I ran it to see what it looked like, but I didn't try to play it so I really didn't understand how it worked -- I mean I got that you shot at things, but did you shoot an any or only the latest, etc... stuff like that.
@@8BitRetroJournalwell, than you played it, despite for a brief moment. Hence, in this video you made a false claim. And a pretty puzzling one, too
@@nneeerrrd again, I didn't play it. After first recovering it from tape, I hit RUN and saw it create the screen and kind of watched without hitting any keys., and didn't really pay close attention as I was just wondering if I recoverd it fully or if it would crash Then, when I actually played it during the video, I wasn't quite sure 100% how it worked but it was pretty easy to figure out. So I had run it previously but not played it, i.e. like watching someone play chess versus playing chess yourself.
With English being the inferiour language it is, I am not surprised you're spelling "misc" out loud "em-eye-es-KAY", while clearly typing a "c".
There were several places where I corrected it with a comment, but yes, i was spelling it out in my mind phonetically...my research area is automatic speech recognition so I spend too much time with phonetic dictionaries.
Спасибо, отличный контент.
Camera wrong angle.