Fun at DC401 this evening

Got to tear apart a Gtech lottery machine.

Here’s what we’ve found out so far – when the machine boots it tries to establish a serial connection. Interesting – the reason is that that you coudl have any number of interfaces that converted to serial, from Frame Relay, X.25, etc.

The printer is an impact printer, not thermal.

The card scanner will read punch cards aka Hollerith could.

In addition the machine has a removable ccd based scanner for reading hte bar codes on tickets. The ccd will scan Code 3 of 9, 128, UPC, EAN, etc.

The processing is all handled by a Z85 chip. The Z85 is a Z80 equivalent. I still remember a lot of the op codes for the Z80 chip as my first computer, a TRS-80 Model 1 Level II 16K machine used a Z80. We did have some debate over paging with a Z80 – I seem to recall it was possible using a few intructions – you could bank sections of RAM and shift them around. This is how graphics were accomplished on the TRS-80. The display was memory mapped.

We need to hookup the correct serial cables just to see what handshake the device is using. And we’ll also have to see if we can dump the ROM’s on the thing, just to see what it expects. Pretty fun though.

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