Some time ago , the cctalk mailing list had some discussion about modifying a 12 sector RK05 pack ( PDP11 ) to make it into a 16 sector for use with the PDP8. This would be very useful for those of us that have few 16 sector but more 12 , I have 1 16 that I dare to put in the drive but about 20 12 sector packs.
However this is a fare exercise and the modified pack would not then be usable as 12 sector and sometime I hope to get my 11/50 running and i might then need them.
So I decided to see if how hard it would be to modify the actual RK05 drive to make it treat a 12 sector as a 16, ie soft sector it. The approach I took was to tap into the M7700, index and sector, pull out the "raw" sector/index" signal, feed this into an external microicontroller, use this to synthesize a 16 sector pulse stream and feed this back to the M7700.
Tonight I successfully formatted a 12 sector pack as 16 sectors, PDP8/m, RK8E, MAINDEC-08-DHRKD-D, rk05J.
WOOPEEE.
Next step is to do a restore of one of David Gesswein's OS8 images and run it for real.
The PIC is the 18F8720 running at 20Mhz, programed in Pascall using the excellent and free mikroPascal compiler, making use of all 5 counter timers !!
When I have done some more testing and tidied it up a bit, the software is a bit rough at present, I will post more details and make it available to others that may be interested.
May even do a utube video if I can remember who I lent my camera to.
Dave H
However this is a fare exercise and the modified pack would not then be usable as 12 sector and sometime I hope to get my 11/50 running and i might then need them.
So I decided to see if how hard it would be to modify the actual RK05 drive to make it treat a 12 sector as a 16, ie soft sector it. The approach I took was to tap into the M7700, index and sector, pull out the "raw" sector/index" signal, feed this into an external microicontroller, use this to synthesize a 16 sector pulse stream and feed this back to the M7700.
Tonight I successfully formatted a 12 sector pack as 16 sectors, PDP8/m, RK8E, MAINDEC-08-DHRKD-D, rk05J.
WOOPEEE.
Next step is to do a restore of one of David Gesswein's OS8 images and run it for real.
The PIC is the 18F8720 running at 20Mhz, programed in Pascall using the excellent and free mikroPascal compiler, making use of all 5 counter timers !!
When I have done some more testing and tidied it up a bit, the software is a bit rough at present, I will post more details and make it available to others that may be interested.
May even do a utube video if I can remember who I lent my camera to.
Dave H