[sdiy] Keyboard scanner IC

[Andre Majorel]

On 2009-01-25 17:26 -0500, Nathan M. Reeves wrote:

> The keyboard is scanned by U1, which is a mask-programmed 6502-variant.
[...]
> Now on the schematics I  downloaded from tom (the original Mirage I  
> believe), things are a bit off from what I see inside the Mirage DSK I  
> am working over...
>
> on mine
> U1 SN74LS145N
> U2 7406N
> U3 7407N
> U4 R6522AP
> U5 WD1772-PH
> U6 1380650001
>
> on the schematics
> U1 6500/11 MCU
> U2 LM339N
> U3 NE555
> U4 6N138
> U5 LM339N
> U6 74LS145
>
> So on my unit U6 is what U1 is on the schematic?  the 6502 variant MCU?

If your unit has a CPU, it has to be U6. U4 (6522) and U5 (1772)
are not CPUs and the others are SSI chips. I don't recognise that
"1380650001" number, however.

-- 
André Majorel <URL:http://www.teaser.fr/~amajorel/>