so I replaced the U79 74LS86 exclusive or gate with a spare 74LS04 inverter. ( I pulled out pin 15 of U74 and connected it to the output of the inverter I used to replace the ls86 gate) this was done to reduce propagation delay the ls86 might have introduced. The result was unfortunately the same, still data not getting written correctly to the 4 bit 1K ram chip.
next replace U20 and U21 or test in my 866 mini pro (it tests ttl chips)
Are there any REV D 600's out there? Bill? Jeff? DAVE? have you guys had a chance to test your 4 bit 1k ram out?
Cheers.
600D Colour RAM. Help!!!! SOLVED!
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Re: 600D Colour RAM. Help!!!!
Turning into quite an OSI Junkie (HTFDTH?) Superboard II REV B-40K, 9600b, HC-05 Bluetooth, Superboard II Rev D, C4P rebuild- 502, 542c, 540B.
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Re: 600D Colour RAM. Help!!!!
I haven’t built mine yet.
/Jeff
/Jeff
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Re: 600D Colour RAM. Help!!!!
okie doke. thanks for replying.
we are so close (by we I mean Steve) to finishing up the
colour board. So figuring out the ram issue would make the colour board,
all the more worth while.
we are so close (by we I mean Steve) to finishing up the
colour board. So figuring out the ram issue would make the colour board,
all the more worth while.
Turning into quite an OSI Junkie (HTFDTH?) Superboard II REV B-40K, 9600b, HC-05 Bluetooth, Superboard II Rev D, C4P rebuild- 502, 542c, 540B.
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Re: 600D Colour RAM. Help!!!!
I wish I could help, but I haven't built mine either.
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Re: 600D Colour RAM. Help!!!!
Thank you for replying
I'm confident that when Josh builds his, (and I have been coaxing him to start...) we will find a solution,
as he is a master of this kind of stuff...
In the mean time, random colours are still kinda cool?
I'm confident that when Josh builds his, (and I have been coaxing him to start...) we will find a solution,
as he is a master of this kind of stuff...
In the mean time, random colours are still kinda cool?
Turning into quite an OSI Junkie (HTFDTH?) Superboard II REV B-40K, 9600b, HC-05 Bluetooth, Superboard II Rev D, C4P rebuild- 502, 542c, 540B.
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- Posts: 325
- Joined: Mon Oct 06, 2008 1:54 pm
- Location: Markham, Ontario, Canada
- Contact:
Re: 600D Colour RAM. Help!!!!
Here's the 99% complete 600D Color board (16-color simplified)...
I'm just tweaking the board routing and labels and will verify fit of the mounting hole and then I'll do a small run (~10) of board.
Steve
The first person to solve the color ram writing issue gets a free blank pcb when complete (pending verification that it AND the fix are working together ).I'm just tweaking the board routing and labels and will verify fit of the mounting hole and then I'll do a small run (~10) of board.
Steve
C4P working, C1P working. 600D Replica working, C4P+D&N floppy not working. 505 board, 610 board, Mittendorf board, TOSIE hacker board need testing, PicoDOS disk untested.
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Re: 600D Colour RAM. Help!!!!
Is this color board based on the 630 color section?
looking at the schematic it looks like you need to cut a trace on the 600d pin pin 10,11 are tied together on j75 these need to be separate when plugging into the color board. cut blue trace
looking at the schematic it looks like you need to cut a trace on the 600d pin pin 10,11 are tied together on j75 these need to be separate when plugging into the color board. cut blue trace
Replica 600 Rev D:8K,CEGMON
Replica 610 Rev B: 24k,MPI B-51 with Custom Data separator D-13
510 on the bench/replica 582 backplane/replica 470a /replica 555/original 570B/2 x Shugart 851
Ongoing : 630 ,620 ,510,542c,custom 590,SA1200,592,594,596,598
Replica 610 Rev B: 24k,MPI B-51 with Custom Data separator D-13
510 on the bench/replica 582 backplane/replica 470a /replica 555/original 570B/2 x Shugart 851
Ongoing : 630 ,620 ,510,542c,custom 590,SA1200,592,594,596,598
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Re: 600D Colour RAM. Help!!!!
Yes, they are tied together, however this is designed to allow the 630 board to invert the video signal using BIT0 from colour ram (the "invert" line) and output to composite video. This does not affect reading or writing, and I also do not use this on my colour board.
Were there any modifications made to the board other than adapting for EPROM and keyboard switches?
Steve
Were there any modifications made to the board other than adapting for EPROM and keyboard switches?
Steve
C4P working, C1P working. 600D Replica working, C4P+D&N floppy not working. 505 board, 610 board, Mittendorf board, TOSIE hacker board need testing, PicoDOS disk untested.
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Re: 600D Colour RAM. Help!!!!
No other changes made other than the roms
I ll check the board to schematic again but all seems to be correct to schematic
I ll check the board to schematic again but all seems to be correct to schematic
Replica 600 Rev D:8K,CEGMON
Replica 610 Rev B: 24k,MPI B-51 with Custom Data separator D-13
510 on the bench/replica 582 backplane/replica 470a /replica 555/original 570B/2 x Shugart 851
Ongoing : 630 ,620 ,510,542c,custom 590,SA1200,592,594,596,598
Replica 610 Rev B: 24k,MPI B-51 with Custom Data separator D-13
510 on the bench/replica 582 backplane/replica 470a /replica 555/original 570B/2 x Shugart 851
Ongoing : 630 ,620 ,510,542c,custom 590,SA1200,592,594,596,598
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- Joined: Mon Oct 06, 2008 1:54 pm
- Location: Markham, Ontario, Canada
- Contact:
Re: 600D Colour RAM. Help!!!!
Good news! The colour writing issue has been solved! Walter, Josh and Myself got together with a logic analyzer and a schematic printout and put our heads together to solve it.... Well, it was mostly Josh as we figured it would be On page 4 of the schematic is an unlabelled jumper at the top right near U56. The jumper defaults to A10. To fix the issue this has to be changed to +5V. We tested and writing is solid.
So, Josh and Walter will both get a free Colour Board! Thanks guys!
Steve
So, Josh and Walter will both get a free Colour Board! Thanks guys!
Steve
Last edited by Steve Gray on Mon Jun 10, 2019 4:30 am, edited 2 times in total.
C4P working, C1P working. 600D Replica working, C4P+D&N floppy not working. 505 board, 610 board, Mittendorf board, TOSIE hacker board need testing, PicoDOS disk untested.