I built my Harlequin from Bytedelight but it didn't work, looking at the instructions it said that usually most people find missed solder joints, to my embarrassment I had missed some solder joints on a chip. All working perfectly now, well worth the effort.
Hi Phil, I should have gone for the Ben's kit but really wanted the challenge of no instructions and sourcing everything myself. I think that back fired on me a little :-) Its all good experience and was super fun to do. Happy new year to you and all the best for 2024.
I've built Harlequin 128 2D (from Bytedelight kit) and Harlequin 128 4B (sourced parts myself). Feel free to ping me if you need probe something. However I suspect that you have a short somewhere - it's worth checking the board under the microscope. Some vias are pretty close to the IC pins, so it's easy to short them.
Thanks Vasily, much appreciated. I messaged Don Superffo and he has pointed out the chips and areas I need to inspect further. I just havent had time to return to the board yet. I will break out the microscope and take a closer look but I was very careful when building but am getting old and my eyes sometimes lie to me :-) Happy new year and all the best for 2024
9 месяцев назад+6
I don't trust resistor colour codes (especially because I don't know the exact method by heart and I am lazy to learn it) but I also don't trust any package prints, so I always test resistors with a multi meter first. Then for sure, I trust enough in the "same colour strips = same value" theory after that, at least :)
Yes, it certainly caused me a big problem until I worked out what had happened. I will be testing them going forward, once bitten twice shy :-) Still, it was a fun project and when I have more time I will get back to diagnosing the issue. Happy new year and all the best for 2024
It just makes future diagnostics and fixing them so much easier to have everything socketed. It must have been a big challenge for the designer to cram so many chips on such a little board and chips under chips was the only way to cram them all in. Direct to board is a lot cheaper on the Harlequin due to the amount of sockets needed but you still need two for the stacked chips. All the best and thanks for watching and commenting.
Take this as a WAG (wild-assed-guess), but it looks like the Harelquin ULA replacement logic is reading invalid data when it is trying to generate the display. That would suggest either that the Z80 contention logic isn't working (and could be compared against a "normal" Spectrum) - or perhaps more likely that the address counters are not managing to put valid values onto the lower ram address bus when reading out video data. A start point might be to check the read patterns on that lower ram chip against a normal Spectrum - even though this is a Harlequin, it should probably be counting up through the address locations in video ram in exactly the same way the Sinclair ULA does.
Hi LockFarm, thank you for your message which is greatly appreciated. I contacted Don Superfo on this and he was very kind and said: The problem is related to Lower RAM (U8), not U8 itself but other signals that control address lines, U38, U23D, U27D, U41, U42. You may try to change U38 if you have spare, U41, U42 are soldered directly to pcb I think they are OK, don't need to change them. I have not had time to revisit the machine but will soon. Would really like to get it working and into a case so I can have fun with it. I think this aligns with what you are saying so should hopefully be a good place to start. All the best and thanks for watching
Respect for all your patience. I didn´t want to go on a hunt for all the parts and pieces needed for my Harlequin 128k build so I went along and ordered the complete kit from Byte Delight. Things went pretty good and everything works fine ! Maybe, the turned pin sockets make a better connection but you have to keep in mind that the chips you use are made with single or dual wipe sockets in mind so I find it much easier to use dual wipes for that purpose as included in the Byte Delight kit. You have to make sure that you use LS-Components and NOT the HC labeled ones since the HC components work with lower voltage levels than the LS ones do (HC o to 3,3 V, LS 0 to 4,5 V).HC components MAY work, but if they don´t , well... :) My Board is a Rev 2D(well, at least I could do the Joystick Mod), so I don´t know whether the newer versions still habe the three jumpers J9,J10 and J11. On my Revision, you have to set them all to the 2-3 position for PAL Video, otherwise you will definitely not get a good looking picture :)
The kit from Bytedelight is great and comes with everything needed. I probably should have gone with that also but was facinated by the IDE connector and wanted to see what that was all about so went with the 3H instead. The 3H board has two switches that can be fitted to alter the timing and switch between PAL and NTSC. SW3 and SW4. Default timing is 128k on SW3 and default is PAL on SW4. To enable these switches you have to cut traces on the board as shown in the assembly pdf on github. Was lots of fun building the Harelquin, hope you are enjoying yours as well. Happy new year and all the best for 2024
You should use be using turned pin female strips as they are much cheaper and can be cut to any length required. they would also allow chips and components to be soldered underneath socketed IC's. When soldering those through hole resistors, simply place them all into the locations and solder one side from the top to hold them into position. You can then flip the board over once without having to bend all the legs as the top solder leg will hold them in place.
I didn't have any strips in so had to butcher sockets :-) Will order some next time I put an order in as would be much quicker as you say. Happy new year and all the best for 2024
Maybe you can use a ribbon cable on the IDE port without cutting the case? I would try to add plastic spacers on the screwholes and lift the upper case half just enough to fiddle the flat IDE cable through the gap. A standing IDE Socket might be better for this.
The issue here is that the IDE socket has been removed on all later revisions of the board so I think it was an idea that has not gathered any momentum. The 48k case is so tight for space but you could probably juggle it and get the ribbon to come out the cart slot without cutting anything but then you loose the cart slot. Easier all round to use a dandanator. You could also cut a slot in the base and feed it out that way but it does say "Simple 8 bit IDE Interface" on the board and nothing further so not sure on what level of support it has re working with drives / devices. All the very best and thanks for watching
Apart from having to cut into the casing, I believe the IDE interface with an HDD connected to it doesn't have much use in Spectrum world. You can't put games in there because there is no way of loading games from there. There may be a way to make it work with +3 disk images, but it will require extra software to mount and emulate those as an FDD. I am speculating here because I never used (or even seen) a Spectrum with a harddisk, maybe there are ways to make it work in a useful manner.
I was surprised to see an IDE connector on the 3H and to see that its been removed from the later two models. If it was still present on the later revisions it would be worth looking into further. Its an interesting addition and would be great to be able to connect up an HDD to the specturm. The Dandinator does a fine job so the effort was probably not worth continuing the idea and hence it was removed. Thanks for taking the time to comment, very much appreciated
I am looking forward to hearing your opinion on the George 2. Been putting off buying a new CB radio until the manufacturers catch up post Covid and post FCC FM.
Hi Gordon, am still waiting for the George 2 to become available. first it was Sept and now its Oct for availability. Hopefully soon it will be available and I can get my grubby mits on one. It looks like its going to be an amazing radio, I have high hopes for this one. All the best and thanks for watching
@@NLKMediaGroup Me too. I am holding off buying a new radio until this one is an option. We have a new CB user group here in Edinburgh and activity is picking up. Its more active than 2m for sure.
Hi, there is a minimum order of x5 boards at PCB Way, it currently costs about $50 for five boards and then shipping ontop. So, about $75 shipped to UK. If you follow the link in the description to PCB Way shared projects you can see the relevant options for buying the boards. Hope this helps and Happy new year to you
Not yet, but there are things happening in the background, hang on a bit longer and more spectrum content will be coming soon. All the best and thanks for commenting. MJ7NLK
Why would the maker of this board use a center negative power socket when most zx power adapters are either failing or failed. I wouldn't risk plugging an old center negaive power adapter into that board. Modern power adapters are all center positive, more reliable and much cheaper.
Well, you are actually supposed to use a modern power supply, you just have to make sure that it is outputting center negative.if needed, change the polarity...
@@hollgo626 modern power adapters are NOT center negative. To conform with safety regs they were changed to have the positive terminal center and unexposed from short circuits.
That is true but not be an issue. Either use a power supply where you can switch the polarity like multi voltage supplies or use a standard power supply with the right voltage and modify it to make it center pin negative. If you manage to build such a complex device as the Harlequin, this will not be a problem for you. You definitely do not have to use those ancient power bricks from the 80s....
@@hollgo626 You totally missed my point. I wasn not asking how to obtain/build switched polarity dc supply. I was making a point as to why the designer of this board chose to use a center negative power input Makes no sense whatsover as no one uses those kind of adpaters and why would you uses your old unreliable zx spectrum power adapter.
I guess it was because most people building a Harlequin would already own ZX Spectrum gear and the risk of plugging in the wrong adapter would be quite high. I have loads of original spectrum power supplies and dont use any of them. I source brand new psu's for the spectrum from Ebay which are modern switching units and cost under £15. Its easy to source centre negative sealed units but there is always a risk of plugging in a centre positive by mistake so always mark the jack end in some way, like coloured heat shrink over the plastic to reduce those senior moments :-) Happy new year and all the best for 2024
Marking is on the cathode usually, will check if I said something else on the video, thanks for pointing out if I got my anode / cathode the wrong way around :-)
I had no problem as I have build over 20 now ,still great video thanks, enjoy it ..ben kit is a very good one ,all you have to do is get your rom ,the rest is dun.
I wanted to try this version as the IDE connector caught my attention (although its now been removed on the V4 boards). I just havent had time to get back to this board and diagnose the issue I was having. Still it was great fun to build. Happy new year RetroRobbins, all the best for 2024.
74LS devices are TTL compatible, 74HC devices are NOT, hence the availability of 74HCT devices - High speed CMOS, TTL compatible. Check that circuit diagram mate. If LS then can use HCT devices but NOT!!! HC devices, unless of course the circuit explicitly states the use of a HC device etc. Oh the subtleties of logic!
After some digging online while trying to diagnose the display issue I came across an article suggesting to try and replace U28 with an LS variant as that seemed to solve the problem for another person. It was worth a try and the machine functions with U28 as HC or LS variants but it did not make any difference for me so swapped it back. next thing I am going to try is to remove the resistors and caps on the other two pins of the scart cable to discount this.
@@NLKMediaGroup @andylewis3461 Harlequin boards explicitly say 74HC on their BOMs, they also use the CMOS variant (Z84Cxxx) of the Z80, all the RAM ICs are also CMOS. There is only one IC that calls for 74AC, which is (if I remember correctly) on the clock generation circuitry. This fault may be anything, in my Harlequin 128 (issue 4A) built couple of years ago, I had a similar problem, and it turned out to be a soldering mistake (omitted to solder one side of one IC totally, good lesson to stop working when you are tired). One other possibility is that the AD724 might have gotten a bit damaged due to excessive heat. I use hot air to de-solder dead ICs, but never to solder them. Drag soldering works perfectly for me even for finer pitched ICs.
Well I watch the video and I have no idea what the item you're building is supposed to do when it is working properly. This video was maybe above my pay grade.
Hi Robert, its a ZX Spectrum clone using modern and available parts, with improvements over the original. Thanks for commenting and for watching the video. All the best
Hi Dark State, this is the second video now with PCB Way sponsorship, has been extremely helpful to have their support on supplying the PCB's. I imagine CCP Spys are a little more advanced than 1980's 8 bit computing :-) Thanks for watching and for commenting
Why does everybody do PCBway ads? They get annoying to the point I hunt for PCB's in India nowadays or go to their competitor. Do you get a free BYD car delivered at your door or what if you show their name? Or do they wire transfer 100 hard Euro's every month? I feels really douchy. Like the real benefit is one free 5 PCB set per year or so.
I built my Harlequin from Bytedelight but it didn't work, looking at the instructions it said that usually most people find missed solder joints, to my embarrassment I had missed some solder joints on a chip. All working perfectly now, well worth the effort.
Hi Phil, I should have gone for the Ben's kit but really wanted the challenge of no instructions and sourcing everything myself. I think that back fired on me a little :-) Its all good experience and was super fun to do. Happy new year to you and all the best for 2024.
I've built Harlequin 128 2D (from Bytedelight kit) and Harlequin 128 4B (sourced parts myself). Feel free to ping me if you need probe something. However I suspect that you have a short somewhere - it's worth checking the board under the microscope. Some vias are pretty close to the IC pins, so it's easy to short them.
Thanks Vasily, much appreciated. I messaged Don Superffo and he has pointed out the chips and areas I need to inspect further. I just havent had time to return to the board yet. I will break out the microscope and take a closer look but I was very careful when building but am getting old and my eyes sometimes lie to me :-) Happy new year and all the best for 2024
I don't trust resistor colour codes (especially because I don't know the exact method by heart and I am lazy to learn it) but I also don't trust any package prints, so I always test resistors with a multi meter first. Then for sure, I trust enough in the "same colour strips = same value" theory after that, at least :)
Yes, it certainly caused me a big problem until I worked out what had happened. I will be testing them going forward, once bitten twice shy :-) Still, it was a fun project and when I have more time I will get back to diagnosing the issue. Happy new year and all the best for 2024
@@NLKMediaGroup .m m,. Mjhuoiooopouoiupp0
😊
I think there is the reasonable balance between socketed chips and fitted directly on a board
It just makes future diagnostics and fixing them so much easier to have everything socketed. It must have been a big challenge for the designer to cram so many chips on such a little board and chips under chips was the only way to cram them all in. Direct to board is a lot cheaper on the Harlequin due to the amount of sockets needed but you still need two for the stacked chips. All the best and thanks for watching and commenting.
Take this as a WAG (wild-assed-guess), but it looks like the Harelquin ULA replacement logic is reading invalid data when it is trying to generate the display. That would suggest either that the Z80 contention logic isn't working (and could be compared against a "normal" Spectrum) - or perhaps more likely that the address counters are not managing to put valid values onto the lower ram address bus when reading out video data. A start point might be to check the read patterns on that lower ram chip against a normal Spectrum - even though this is a Harlequin, it should probably be counting up through the address locations in video ram in exactly the same way the Sinclair ULA does.
Hi LockFarm, thank you for your message which is greatly appreciated. I contacted Don Superfo on this and he was very kind and said: The problem is related to Lower RAM (U8), not U8 itself but other signals that control address lines, U38, U23D, U27D, U41, U42. You may try to change U38 if you have spare, U41, U42 are soldered directly to pcb I think they are OK, don't need to change them.
I have not had time to revisit the machine but will soon. Would really like to get it working and into a case so I can have fun with it. I think this aligns with what you are saying so should hopefully be a good place to start. All the best and thanks for watching
Respect for all your patience. I didn´t want to go on a hunt for all the parts and pieces needed for my Harlequin 128k build so I went along and ordered the complete kit from Byte Delight.
Things went pretty good and everything works fine !
Maybe, the turned pin sockets make a better connection but you have to keep in mind that the chips you use are made with single or dual wipe sockets in mind so I find it much easier to use dual wipes for that purpose as included in the Byte Delight kit. You have to make sure that you use LS-Components and NOT the HC labeled ones since the HC components work with lower voltage levels than the LS ones do (HC o to 3,3 V, LS 0 to 4,5 V).HC components MAY work, but if they don´t , well... :) My Board is a Rev 2D(well, at least I could do the Joystick Mod), so I don´t know whether the newer versions still habe the three jumpers J9,J10 and J11. On my Revision, you have to set them all to the 2-3 position for PAL Video, otherwise you will definitely not get a good looking picture :)
The kit from Bytedelight is great and comes with everything needed. I probably should have gone with that also but was facinated by the IDE connector and wanted to see what that was all about so went with the 3H instead. The 3H board has two switches that can be fitted to alter the timing and switch between PAL and NTSC. SW3 and SW4. Default timing is 128k on SW3 and default is PAL on SW4. To enable these switches you have to cut traces on the board as shown in the assembly pdf on github. Was lots of fun building the Harelquin, hope you are enjoying yours as well. Happy new year and all the best for 2024
You should use be using turned pin female strips as they are much cheaper and can be cut to any length required. they would also allow chips and components to be soldered underneath socketed IC's. When soldering those through hole resistors, simply place them all into the locations and solder one side from the top to hold them into position. You can then flip the board over once without having to bend all the legs as the top solder leg will hold them in place.
I didn't have any strips in so had to butcher sockets :-) Will order some next time I put an order in as would be much quicker as you say. Happy new year and all the best for 2024
Maybe you can use a ribbon cable on the IDE port without cutting the case? I would try to add plastic spacers on the screwholes and lift the upper case half just enough to fiddle the flat IDE cable through the gap. A standing IDE Socket might be better for this.
The issue here is that the IDE socket has been removed on all later revisions of the board so I think it was an idea that has not gathered any momentum. The 48k case is so tight for space but you could probably juggle it and get the ribbon to come out the cart slot without cutting anything but then you loose the cart slot. Easier all round to use a dandanator. You could also cut a slot in the base and feed it out that way but it does say "Simple 8 bit IDE Interface" on the board and nothing further so not sure on what level of support it has re working with drives / devices. All the very best and thanks for watching
Good Video ! you should use your gimbal for the cinematic shot of the board next time
Apart from having to cut into the casing, I believe the IDE interface with an HDD connected to it doesn't have much use in Spectrum world. You can't put games in there because there is no way of loading games from there. There may be a way to make it work with +3 disk images, but it will require extra software to mount and emulate those as an FDD. I am speculating here because I never used (or even seen) a Spectrum with a harddisk, maybe there are ways to make it work in a useful manner.
I was surprised to see an IDE connector on the 3H and to see that its been removed from the later two models. If it was still present on the later revisions it would be worth looking into further. Its an interesting addition and would be great to be able to connect up an HDD to the specturm. The Dandinator does a fine job so the effort was probably not worth continuing the idea and hence it was removed. Thanks for taking the time to comment, very much appreciated
I am looking forward to hearing your opinion on the George 2. Been putting off buying a new CB radio until the manufacturers catch up post Covid and post FCC FM.
Hi Gordon, am still waiting for the George 2 to become available. first it was Sept and now its Oct for availability. Hopefully soon it will be available and I can get my grubby mits on one. It looks like its going to be an amazing radio, I have high hopes for this one. All the best and thanks for watching
@@NLKMediaGroup Me too. I am holding off buying a new radio until this one is an option. We have a new CB user group here in Edinburgh and activity is picking up. Its more active than 2m for sure.
Hi. How much was the PCB?
Hi, there is a minimum order of x5 boards at PCB Way, it currently costs about $50 for five boards and then shipping ontop. So, about $75 shipped to UK. If you follow the link in the description to PCB Way shared projects you can see the relevant options for buying the boards. Hope this helps and Happy new year to you
@@NLKMediaGroup Thank you for your reply.
Belated Merry Christmas, and a Happy New Year to you and all your family, too!
Still no luck? No 2nd part of this video?
Not yet, but there are things happening in the background, hang on a bit longer and more spectrum content will be coming soon. All the best and thanks for commenting. MJ7NLK
Why would the maker of this board use a center negative power socket when most zx power adapters are either failing or failed. I wouldn't risk plugging an old center negaive power adapter into that board. Modern power adapters are all center positive, more reliable and much cheaper.
Well, you are actually supposed to use a modern power supply, you just have to make sure that it is outputting center negative.if needed, change the polarity...
@@hollgo626 modern power adapters are NOT center negative. To conform with safety regs they were changed to have the positive terminal center and unexposed from short circuits.
That is true but not be an issue. Either use a power supply where you can switch the polarity like multi voltage supplies or use a standard power supply with the right voltage and modify it to make it center pin negative. If you manage to build such a complex device as the Harlequin, this will not be a problem for you. You definitely do not have to use those ancient power bricks from the 80s....
@@hollgo626 You totally missed my point. I wasn not asking how to obtain/build switched polarity dc supply. I was making a point as to why the designer of this board chose to use a center negative power input Makes no sense whatsover as no one uses those kind of adpaters and why would you uses your old unreliable zx spectrum power adapter.
I guess it was because most people building a Harlequin would already own ZX Spectrum gear and the risk of plugging in the wrong adapter would be quite high. I have loads of original spectrum power supplies and dont use any of them. I source brand new psu's for the spectrum from Ebay which are modern switching units and cost under £15. Its easy to source centre negative sealed units but there is always a risk of plugging in a centre positive by mistake so always mark the jack end in some way, like coloured heat shrink over the plastic to reduce those senior moments :-) Happy new year and all the best for 2024
I thought that the band on the diode was on the cathode.
Marking is on the cathode usually, will check if I said something else on the video, thanks for pointing out if I got my anode / cathode the wrong way around :-)
Yup, I said Anode by mistake, have added a correction to the video desciption, thanks for pointing this out.
I had no problem as I have build over 20 now ,still great video thanks, enjoy it ..ben kit is a very good one ,all you have to do is get your rom ,the rest is dun.
I wanted to try this version as the IDE connector caught my attention (although its now been removed on the V4 boards). I just havent had time to get back to this board and diagnose the issue I was having. Still it was great fun to build. Happy new year RetroRobbins, all the best for 2024.
👍👍👍✌👏
Thank you @Chiavaccio, all the best MJ7NLK
@@NLKMediaGroup 😊😊👋👋👍
74LS devices are TTL compatible, 74HC devices are NOT, hence the availability of 74HCT devices - High speed CMOS, TTL compatible. Check that circuit diagram mate. If LS then can use HCT devices but NOT!!! HC devices, unless of course the circuit explicitly states the use of a HC device etc. Oh the subtleties of logic!
74LS devices can only drive one TTL input while TTL can drive 10 TTL inputs. So, in some cases it's fine, some, not so much.
After some digging online while trying to diagnose the display issue I came across an article suggesting to try and replace U28 with an LS variant as that seemed to solve the problem for another person. It was worth a try and the machine functions with U28 as HC or LS variants but it did not make any difference for me so swapped it back. next thing I am going to try is to remove the resistors and caps on the other two pins of the scart cable to discount this.
@@NLKMediaGroup @andylewis3461 Harlequin boards explicitly say 74HC on their BOMs, they also use the CMOS variant (Z84Cxxx) of the Z80, all the RAM ICs are also CMOS. There is only one IC that calls for 74AC, which is (if I remember correctly) on the clock generation circuitry. This fault may be anything, in my Harlequin 128 (issue 4A) built couple of years ago, I had a similar problem, and it turned out to be a soldering mistake (omitted to solder one side of one IC totally, good lesson to stop working when you are tired). One other possibility is that the AD724 might have gotten a bit damaged due to excessive heat. I use hot air to de-solder dead ICs, but never to solder them. Drag soldering works perfectly for me even for finer pitched ICs.
Well I watch the video and I have no idea what the item you're building is supposed to do when it is working properly. This video was maybe above my pay grade.
Retro rubbish is what it is
It is a great clone of the legendary Sinclair Spectrum computer. Retro, yes, rubbish NO!
Hi Robert, its a ZX Spectrum clone using modern and available parts, with improvements over the original. Thanks for commenting and for watching the video. All the best
Dude. 3.3k Subs. PCB Way ads already?
Are you a CCP spy?
Hi Dark State, this is the second video now with PCB Way sponsorship, has been extremely helpful to have their support on supplying the PCB's. I imagine CCP Spys are a little more advanced than 1980's 8 bit computing :-) Thanks for watching and for commenting
@@NLKMediaGroup thank you for handling the reply so nicely 🙏💚
Why does everybody do PCBway ads? They get annoying to the point I hunt for PCB's in India nowadays or go to their competitor.
Do you get a free BYD car delivered at your door or what if you show their name? Or do they wire transfer 100 hard Euro's every month? I feels really douchy. Like the real benefit is one free 5 PCB set per year or so.