JAMMArcade.net – Page 21

Server move and down time

General Comments Off

May 302019

The usual visitors to this site will have noticed that it has been offline for a few days.
Basically the site had grown too big for for our hosting and I made the decision to move.
Obviously this comes at a cost and for a time I thought I was going to have to make some compromises.
Luckily, for this year at least, I had a cash injection from Banjo Guy Ollie & Caius which has allowed me to pay for what was needed.

I am contemplating setting up a Patreon or something in order to help pay for this cost going forward.
We will see how it goes.

Massive thanks to Banjo Guy Ollie & Caius for the contributions.

6116 to Sony CXK5808 RAM adapter

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May 262019

The Sony CXK5808 is a 1k x 8-bit RAM of which we know very little about, no datasheet from manufacturer is available, we can only find its pinout on schematics of arcade PCBs.It’s a 400mil DIP22 IC:

Therefore time ago I designed a simple adapter in order to use a common 6116 (or other 300mil DIP24 2k x 8-bit RAM device) in place of this obscure and hard to find part :

Here’s testing of the adapter on my Gun.Smoke PCB:

Nemesis (Konami GT conversion) repair log

PCB Repair Logs Comments Off

May 252019

Received from Portugal a faulty Nemesis PCB for repair, actually a conversion from Konami GT on GX400 hardware.Set is made of a CPU board :

And a VIDEO board :

The game was full playbale with sound but the graphics were glitched as there were jail bars all over the screen:

The fault was obviously located on the bottom VIDEO board therefore first of all I ruled out all the custom ICs by swapping them in a good board, they were all OK.Then I focused on a couple of rows of 4164 dynamic RAMs (some were already replaced) :

They are 64K x 1-bit devices, here’s pinout :

On this board they are used as sprite line buffer like schematics show :

I went to probe them with my scope and I found one with an unhealthy signal on data output pin (good signal for comparison on left of below picture) :

It was the chip @5H which I prompty removed and replaced with a good one :

This fixed the issue and board competely.Repair accomplished.

BINman update

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May 212019

Quick update here.

One small bug fix with the byte sum not clearing when reset.
The analysis routine has been updated to check if alternate bytes are stuck high, low or are all the same.

I think that’s all. There may be other things too but its been a while and I’ve forgotten what they might be.
I’ve since started using source control for my projects so will be able to keep better track of things

Data I/O 29A repair log

Equipment Repair Logs Comments Off

May 212019

I’m not dead!
Some time ago I scored a great deal on eBay for a Data I/O 29A setup with a load of modules and manuals.
Pretty much everything worked great apart from the display was really dim.
It doesn’t look too bad in the picture but it looked much worse in real life

Schematics are readily available for the unit so fault finding was fairly quick.
With the display being dim my initial though was a voltage issue and the schematics have conveniently labelled the area up as “FILAMENT SUPPLY GENERATOR”.

Using the scope I could see straight away the CD4049 hex inverter at U14 was not inverting at all.
Simply replacing this fixed the fault

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