Atari Black Widow/Gravitar

Black Widow ROM Placement

Copyright 198? Atari. Program by ?????.

Black Widow
NAME LOCATION SIZE CHECKSUM
---------- -------- ---- --------
136017.101 D1 2532 65AD
136017.102 E/F1 2532 A892
136017.103 H1 2532 EB47
136017.104 J1 2532 9A5E
136017.105 K/L1 2532 88DF
136017.106 M1 2532 6482
136017.107 L7 2716 0285
136017.108 M/N7 2532 D5A0
136017.109 N/P7 2532 D081
136017.110 R7 2532 0378

NEED:
136002.125 Location: N4
136010.111 Location: R1



These are the Gravitar eproms, a 2532 and a 2716 are neeed for the small one.
136010.201 - 136010.206 are code the other 4 are vector roms. 136010.210 is the small one.

The files are binary format.

On the board here is the placement:

Code first
D1 136010.201 4K 2532
E/F1 136010.202 "
H1 136010.203 "
J1 136010.204 "
K/L1 136010.205 "
M1 136010.206 "

Vector rom
M/N7 136010.207 "
N/P7 136010.208 "
R7 136010.209 "
L7 136010.210 2K 2716
 
What ones are numbered differently? I want to make sure I get them in the right spots.

The four graphics ROMS for Black Widow are numbered (in order as they appear in the middle column of the board, top to bottom):
110
109
108
107

On Gravitar they are ordered:
109
108
107
110

In both cases the top three are 2532's, and the bottom one is a 2716.
 
The four graphics ROMS for Black Widow are numbered (in order as they appear in the middle column of the board, top to bottom):
110
109
108
107

On Gravitar they are ordered:
109
108
107
110

In both cases the top three are 2532's, and the bottom one is a 2716.
Thanks for the infos, am i wrong, it doesn't correspond to the retrofit manual from gravitar to black widow
 

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Ok look like i check on the wrong side 🙂🙂


Yes. When we talk about Atari (and a lot of other) boards, we usually refer to them with the edge connector on the right-hand side. This is because that's how they are usually installed in the cabinets, and the columns on the board are labeled 1 though X, where column 1 is on the left side (so the numbers increase left to right). Also, the functional flow of how things work tends to flow from left to right (starting with the CPU on the left, then the vector generator in the middle, then the video outputs on the right.) Schematics also tend to be written left-to-right.

This is just the convention most people use. Even though it's confusing when you're new, because it results in the printing on most of the chips being upside down. But we live with that, because it makes everything else more intuitive.
 
Yes. When we talk about Atari (and a lot of other) boards, we usually refer to them with the edge connector on the right-hand side. This is because that's how they are usually installed in the cabinets, and the columns on the board are labeled 1 though X, where column 1 is on the left side (so the numbers increase left to right). Also, the functional flow of how things work tends to flow from left to right (starting with the CPU on the left, then the vector generator in the middle, then the video outputs on the right.) Schematics also tend to be written left-to-right.

This is just the convention most people use. Even though it's confusing when you're new, because it results in the printing on most of the chips being upside down. But we live with that, because it makes everything else more intuitive.
Thanks a lot for those infos, very apreciated !!🙂🙂
 
No problem.

I should have added, the audio section mods can give you clues as to whether the board was factory-converted or not, because there's a certain look to factory rework, versus if someone did it later. It's just a little cleaner, and the cap they used to change the value of C27 will be consistent with the type Atari used (which is a fat red double-humped type, similar to the ones you'll see in the video section.) Whereas if someone did the mods in the field, it will probably be a different brand. Atari also will have clipped C28 and C34 off from the parts side, rather than desoldering them, because it was faster.

Details on doing the audio mods are here (and in the doc VC linked above), and are summarized below:



But it's basically 4 things:

- Change C27 from 1000pF to 100pF (increases LPF BW, to play higher sounds)
- Remove C28 (1000pF) (disables LPF, to play higher sounds)
- Remove C34 (0.22uF) (disables LPF, to play higher sounds)
- Change R46 from 10k to 22k (changes mixing of the two pokey audio outputs)

Also, when going from G to BW, the EAROM must be erased via the BW test menu as a final step, else BW will throw EQP errors, and the scaling test mode will have thumps instead of tones.

This tracks with the board in the game I picked up yesterday, FWIW. At least one pot in the vector section was replaced at some point in its life as well:

IMG_5127.jpg
 
This tracks with the board in the game I picked up yesterday, FWIW. At least one pot in the vector section was replaced at some point in its life as well:

View attachment 825112


Yes. The audio section rework on that one looks like it was done at the factory, because of the types of caps used.

(Also FYI, replace that AVG chip! Originals should always be replaced on these, as they are a high failure part, and will usually take out your monitor when they go. So it's not worth the risk, even if the original chip is still working.)
 
Yes. The audio section rework on that one looks like it was done at the factory, because of the types of caps used.

(Also FYI, replace that AVG chip! Originals should always be replaced on these, as they are a high failure part, and will usually take out your monitor when they go. So it's not worth the risk, even if the original chip is still working.)

Good info, thanks. I have a spare on hand.
 
Yes. The audio section rework on that one looks like it was done at the factory, because of the types of caps used.

(Also FYI, replace that AVG chip! Originals should always be replaced on these, as they are a high failure part, and will usually take out your monitor when they go. So it's not worth the risk, even if the original chip is still working.)

Are you better off with one of the new repros, or an NOS AVG?
 
Looks like the Ebay seller pm-sam hasn't sold any of his custom AVG chips recently, and doesn't plan on making any more any time soon:

I do not have any AVG chips in stock and I don't plan on making anymore anytime soon. The cost of the components has double which makes it economically unfeasible to build more. If I do find some components at a reasonable price I may start building then again

https://forums.arcade-museum.com/threads/which-atari-avg-replacement-is-best.492797/

The Ebay seller sdotaboz sells at least 2 TTL variants of a different custom AVG, but at $50 each. Arcadeshop still has CPLD ones for $25.
 

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Are you better off with one of the new repros, or an NOS AVG?


Who has NOS AVG's?

You might be ok with a NOS, we really don't know. But given that we DO know they fail eventually, I'd still go with a repro. Just given how critical the part is.

You're usually talking 100-200 dollars of monitor damage if it fails. So not worth the gamble.
 
I know people love to flip them shit but Alan-1 makes a replacement too.

 
Who has NOS AVG's?

You might be ok with a NOS, we really don't know. But given that we DO know they fail eventually, I'd still go with a repro. Just given how critical the part is.

You're usually talking 100-200 dollars of monitor damage if it fails. So not worth the gamble.

It was in the back of my mind that I had an NOS on hand, but when I dug it out it was a repro, so no worries there.

(But I think you can still get NOS AVG's from Brad at Best Electronics if you really wanted one.)
 
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