Synaesthesia Posted June 13, 2020 Share Posted June 13, 2020 (edited) Picked up a 1040STF recently and have been tinkering. It came with a bad attempt at floppy drive cable reinstallation and some keys were funny. Tackled the floppy drive first by soldering a header on for data to use a standard cable and got a GOTEK drive sorted for it. However since doing that, the keyboard has stopped functioning completely - as has the mouse. No clicks when you keep keys pressed down etc. Power light is on and there is a very, very feignt flickering of the FDD activity light. Have tried another keyboard and has the same symptoms and have carried out basic diagnostic where I can; the schematic I have is for a different version of the mainboard (mine is C070859-001) so some things differ to others - pin 7 of keyboard connector on others goes to the RESET signal - on mine it goes to ground. Obviously +5v on pin 3 appears OK for the lights to do something. Worrying i've worsened or created a new problem around the floppy connector I've reflowed all that including the nearby chip but also hasn't appeared to help. Just to absolutely rule out 2 duff keyboards Ive changed the buffer chip to no avail. Is there anything else I should be doing to check, any common faults etc? Looking around here, youtube etc the only common issues seem to center around the buffer. Huge thanks (This is all with the motherboard out of the chassis and all drives removed) Edited June 13, 2020 by Synaesthesia Quote Link to comment Share on other sites More sharing options...
snarkdluG Posted June 13, 2020 Share Posted June 13, 2020 Keyboards can be swapped around between ST(f,m), STe, Falcon. It's the same connector. (Except for the really old ones with joy/mouse port on motherboard). Pin 1 and 8 are ground. Pin 2 is missing so maybe you didn't count that? Is the reset circuit on the Atari working? Try reflow connector and check cable. Try swapping ACIA (6850) around. One controls MIDI and the other one keyboard. But it is the same chip. It is probably some cold joint or bad connection on the motherboard. Measure that you got +5 and ground on keyboard. Also check pin/cable Tx/Rx on keyboard is connected all the way. PSU recapped? Got good 5V and 12V? (12V not need for floppy or keyboard though). But floppy/gotek is working? Quote Link to comment Share on other sites More sharing options...
Synaesthesia Posted June 13, 2020 Author Share Posted June 13, 2020 Cheers. Yeah floppy appears OK. I note 5v is closer to 4.8 but that seems to be normal for these things. Will try swapping those chips, cheers Did indeed count pin 2 yes. Is there a method of testing the reset circuit? (reset switch works, also pin 7 is noted as reset signal on the keyb connector its actually ground (and is suppoised to be) Quote Link to comment Share on other sites More sharing options...
snarkdluG Posted June 14, 2020 Share Posted June 14, 2020 4.8V is within spec I think. +/-5% on 5V is acceptable. So in theory it should work. Atari is 30y old now and many components is not within specs anymore. Capacitors dry out. But lower voltage and will become unstable. I checked on one of my SR98 PSU which I have recapped and I have 5.19V on the connector on the keyboard. I looked at the datasheet for SR98 and it says it should do 5.1V on output rail and +/-0.255V. I don't know if other PSU have other specs. You measured the PSU with load on/connected to Atari I hope? Maybe you should consider recapping the PSU or at least turn the resistor (if there is one) on the PSU to get 5V. Reset is high (5V) when system is running and low (close to 0V) a couple of 100 milliseconds when reset is pressed and released if I remember correctly. If it is GND then you got a short somewhere. Solder bridge between two legs somewhere? Quote Link to comment Share on other sites More sharing options...
Synaesthesia Posted June 14, 2020 Author Share Posted June 14, 2020 Argh rookie mistake, I see what you mean now about the pins So yes, reset is fine and that power is under load. It's one of those crappy Tokin power supplies, I'll recap that tonight. Have ordered replacements for U52 and U54 as they were a pig to get out even with a soldering gun, so rather than risk putting them back in a pair of new ones wasnt even £6. Cheers Quote Link to comment Share on other sites More sharing options...
KLund1 Posted June 15, 2020 Share Posted June 15, 2020 I would suggest reseating the controller IC on the keyboard if it is socketed. And/or swapping it with known good part. I have several keyboards with bad chips on them. Anyone know where to source more? Quote Link to comment Share on other sites More sharing options...
snarkdluG Posted June 15, 2020 Share Posted June 15, 2020 15 hours ago, KLund1 said: I would suggest reseating the controller IC on the keyboard if it is socketed. And/or swapping it with known good part. I have several keyboards with bad chips on them. Anyone know where to source more? https://www.utsource.net/sch/hd6301v1p.html Quote Link to comment Share on other sites More sharing options...
bfollowell Posted June 15, 2020 Share Posted June 15, 2020 Well, none of those are reasonably priced, or even seem to be available. Assuming snarkdluG has the chip number right, you should find much more economical choices here: https://www.ebay.com/sch/i.html?_from=R40&_nkw=HD6301V1P&_sacat=0&_sop=15 Check your local ebay if you're not in the U.S. Quote Link to comment Share on other sites More sharing options...
snarkdluG Posted June 15, 2020 Share Posted June 15, 2020 (edited) 42 minutes ago, bfollowell said: Well, none of those are reasonably priced, or even seem to be available. Looks to be around the same price as on ebay to be honest. They are available, just check the stock they have under the price. If they have over 150000 of them it is just a lie. The chip is obsolete, ie it is not made anymore. The number is written on the chip. I just checked on a keyboard myself. Not that hard. Edited June 15, 2020 by snarkdluG Quote Link to comment Share on other sites More sharing options...
bfollowell Posted June 15, 2020 Share Posted June 15, 2020 (edited) Ok, I must’ve missed something. When I clicked on the link, I saw prices of several thousand dollars each. I just checked again and it looks like you are correct. It’s just really strange pricing. I thought it was a comma, but it was a period. I’ve just never seen things priced down to a thousandth of a cent before. Sorry about that. Edited June 15, 2020 by bfollowell Quote Link to comment Share on other sites More sharing options...
KLund1 Posted June 15, 2020 Share Posted June 15, 2020 I got 10 for $3.8 each, and $10 slow shipping. Not bad. I hope they work. I will use the extras to get the German, and UK keyboards I have in storage working. Synaesthesia - sorry for highjacking you thread. What is your progress? Quote Link to comment Share on other sites More sharing options...
KLund1 Posted July 12, 2020 Share Posted July 12, 2020 These chips finally arrived and this look like new. I tried them all in a MSTE, ST, & Falcon keyboard and none work. Are these chips the need some programming added or are they just plug and play? Thanks Quote Link to comment Share on other sites More sharing options...
Almerian Posted July 12, 2020 Share Posted July 12, 2020 52 minutes ago, KLund1 said: These chips finally arrived and this look like new. I tried them all in a MSTE, ST, & Falcon keyboard and none work. Are these chips the need some programming added or are they just plug and play? Thanks You need the specific Atari keyboard controller, it has code in ROM in it. Quote Link to comment Share on other sites More sharing options...
KLund1 Posted July 14, 2020 Share Posted July 14, 2020 On 7/12/2020 at 3:16 PM, Almerian said: You need the specific Atari keyboard controller, it has code in ROM in it. That figures! I wish those above had mentioned that. Now I'm stuck with 10 useless chips. Or can my chips be programmed with a TL688 II ? In not how can I find Atari chips? Quote Link to comment Share on other sites More sharing options...
Almerian Posted July 14, 2020 Share Posted July 14, 2020 8 hours ago, KLund1 said: That figures! I wish those above had mentioned that. Now I'm stuck with 10 useless chips. Or can my chips be programmed with a TL688 II ? In not how can I find Atari chips? CO70122 from Best Electronics in the US, or from here: https://www.ebay.com/itm/NEW-Atari-520-1040-ST-STE-Mega-TT-Falcon-030-computer-keyboard-IC-chip-C070122/152380452432 Quote Link to comment Share on other sites More sharing options...
Synaesthesia Posted July 15, 2020 Author Share Posted July 15, 2020 Sorry for going radio silent on this! Yes, I'm back up and running after replacing the line buffer on the keyboard and the 2 6850 controllers/ The latter set me back under £8 for the pair delivered, and 5 line buffers cost £6. They're not full controllers so not sure what people are saying about requiring atari specific stuff unless I misunderstood. Purchased from ebay - SN74LS244N OCTAL BUFFER AND LINE DRIVER - 5 off and MC6850P DIP- 24 Integrated Circuit from ON Semiconductor Overall very pleased. Installed HxC firmware onto the Gotek and carried out the required modifications for a dial and on screen display rather than relying on the built in one and works extremely well. Now pondering whether to invest in a RAM upgrade to bring it up to 4mb or just throw it on ebay as is. Or I'll just end up playing countless rounds of Canon fodder again! :D Quote Link to comment Share on other sites More sharing options...
Almerian Posted July 16, 2020 Share Posted July 16, 2020 6 hours ago, Synaesthesia said: Sorry for going radio silent on this! Yes, I'm back up and running after replacing the line buffer on the keyboard and the 2 6850 controllers/ The latter set me back under £8 for the pair delivered, and 5 line buffers cost £6. They're not full controllers so not sure what people are saying about requiring atari specific stuff unless I misunderstood. You misunderstood. Different IC. The 6850 is not the keyboard controller. The 6850 communicates with the keyboard controller(HD6301V1P CO70122), which is a part of the keyboard. Quote Link to comment Share on other sites More sharing options...
ijor Posted July 16, 2020 Share Posted July 16, 2020 On 7/14/2020 at 4:56 AM, KLund1 said: That figures! I wish those above had mentioned that. Now I'm stuck with 10 useless chips. Or can my chips be programmed with a TL688 II ? It can't be programmed with an EPROM burner, the ROM is factory programmed. One could think that there should be a model variant that does have EPROM, but if exists, it is not mentioned in the datasheet. It is possible to use it with external ROM, but this usage is not compatible with the ST keyboard. Quote Link to comment Share on other sites More sharing options...
Synaesthesia Posted July 16, 2020 Author Share Posted July 16, 2020 Oh, my apologies! Are they prone to failure? There's quite a lot of protection between it and the board; with it being the first point of contact for spilled drinks and the like could it be any of the resistors in line going to the cable for the mainboard being corroded? Quote Link to comment Share on other sites More sharing options...
Like us on Facebook
Follow us on Twitter
AtariAge on Instagram
Watch us on YouTube
Chat on Discord
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.