[sdiy] Keyboard scanner IC

[Nathan M. Reeves]

yes i think the only chip that is bad is the 6500/11 MCU
the floppy drive loads samples and the os fine, so the 1772 seems to  
be fine....
not sure what the 6522 does, i guess it also has to do with the floppy  
drive, which is ok...
anyone with the MCU?
cheers
nate

On Jan 26, 2009, at 1:12 PM, Roy J. Tellason wrote:

> On Monday 26 January 2009 02:04:01 am Andre Majorel wrote:
>> 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.
>
> The 6522 is a parallel interface chip,  used also in the VIC-20 and  
> the 1541
> disk drive,  I have some if anybody needs some.  The 1772 is a floppy
> controller interface chip,  I don't have any of those.
>
> -- 
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> be killed but can't be tamed.  --Robert A. Heinlein, "The Puppet  
> Masters"
> -
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> lies. --James
> M Dakin
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