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CS/A65 PETIO

This board implements Commodore PET compatible I/O interfaces. This includes the keyboard, IEEE488, userport (mostly) and tape ports. It adds the functionality that the IEEE488 bus can also be used as a device.
  •  
    20240215 Added version 1.3B that corrects IEEE488 term resistors, opts to block only 8 addresses for each PIA instead of 16.
  •  
    20220313 Added version 1.3A that uses 74LS641-1 instead of MC3446 (untested)
  •  
    20211121 Added version 1.2B that can finally work as a drive for other PETs again.
  •  
    20211018 Added version 1.1E
 

Table of content

Version: 1.3B

Status: ok

Notes

 
This board has been tested as patched 1.3A only so far
 
The PDF layout file contains the description of the jumper settings.

Version: 1.3A

Status: ok (with IEEE488 pullups only)

Notes

 
This board works, only the IEEE488 termination resistors should be populated as pullup only (the 2.4k pulldown is wrong). This is fixed in V1.3B.

Version: 1.2B

Status: untested

Notes

 
The schematics has been tested, now the board can work as a drive for other PETs.

Version: 1.1E

Status: untested

Notes

 
The layout has been overhauled to include better power supply and ground networks.

Version: 1.1D

Status: untested

Notes

 
This board has an additional diode (e.g. 1N4148) to accomodate for the WDC65SC22's totem-pole /IRQ output, as opposed to the orginal's open-collector output. Additionally it clears the board area under the piezo beeper.

Version: 1.1C

Status: ok

Notes

 
This board has the keyboard connector bug from revision 1.1B fixed.

Version: 1.1B

Status: prototype with bug

Notes

 
This board has been tested with a Commodore PET ROM.
 
The 25-pin D-Sub keyboard connector has the wrong keyboard layout. Silly me, relying on the Commodore documentation, in this case the 8296 addendum to the 8032 manual - it has the wrong pinout listed.
 
The use of the IEEE488 interface as device, not controller has not been tested yet.
 
I did not really find a fitting piezo beeper device in the Eagle(tm) libraries, so please make sure you do not make short circuits. Best is to isolate the beeper from the board.
Last modified: 2024-02-15

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