Building a repro Quantum PCB / cabaret

for c63, the bom says its 220pf, the manual says 2200pf...can anyone confirm which one to use?
 
C63 is part of the Z intensity drive circuit. Shown in derived-build BOM and schematic.
Sometimes, if in doubt, check similar schematics. In this case, Gravitar also validates 220pF in that particular circuit.

C63220pFcapMouser80-C410C221J1GKemetC410C221J1G5TA

NOTE: in the Q manual, there are several mistakes ... 2220pF does not exist. Also the Atari part number has a 221 suffix, which implies 220pF.
So, if you sum up, from the manual and schematic and other references, the correct notations and the one bad one, you can make a good assumption on which value is correct.
 
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What VC said. It's 220pF.

The parts list in the Q manual says 2200pF, but the PCB drawing and schems say 220pF.

And yes, using the Gravitar (and even Tempest) schematics for comparison can be useful, as they're all very similar. But there are slight differences.
 
No, the manual is an OBVIOUS TYPO. One too many twos.

2220pf.jpg


The only caps with this specific capacitance that I know of are in the kV range, which is not applicable here.

std%2520cap1.png
 
For the ram... just wanted to confirm these toshiba 2016's and signetics? 2128's will suffice.

20241221_122143.jpg
20241221_122132~2.jpg
 
Synertek SY2128-3 have 150nsec access times. The TMM2016P (no -x) have same rating. Should work.
There are a couple of Q threads here on KLOV discussing compatible RAM for these boards - even if they have a faster/slower speed rating.
When you power up the board, any timing issues will be obvious.

Quote from Bill BITD:

"Note that although some photos included in this package shown UM6116-2 static ram chips installed, they did not work reliably.
They often failed the powerup test. They were replaced by SRM2016C12 and LH5116-15 chips which worked fine."




 
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I built my Quantum Reproduction PCB a few years ago. Lots of time invested, yes roll pin sockets were not a good choice, but at the time I had a plethora of them on hand. My pcb is still working with no issues. Enjoy the my video....

 

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i inventoried the parts i still need and have a couple questions...

10k - 74s86 - can i use 74ls86?
7f - 82s25 - is there a modern sub for this part or gamble with a used pull?
3r - X2212 - has anyone used any of the replacement products for this chip, or take a gamble with a used pull?
 
Yes LS probably would work for this XOR
10K74S86ICMouser - OOS/Obsolete595-SN74S86NTexas InstrumentsSN74S86N

Pull, or Ebay or Arcadechips.com for this RAM
7489 / 74189 / 74289/ 82S25 RAM
7F82S25ICArcadechips.com82S25Texas Instruments74S289

Pull, or Ebay or Arcadechips.com
3RX2212ICArcadechips.comX2212XicorX2212P
 
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