MYARC HFDC V12 Eprom Source Code

[+9640News]

I think this was made available years ago, however I came across it today and archived the files in the event they were not seen, etc.

 

Beery

 

HFDCV12

[atrax27407]

Isn't that the one that was hopelessly buggy?

Edited November 18, 2019 by atrax27407

[+9640News]

I don't know.  I know of no other source code out there for it, so it is what it is.

 

Beery

 

[atrax27407]

 

 

That version had some serious problems. V11 was the last official release. Tony Knerr did three subsequent releases - V14 (reduced the head step times), V15 (removed floppy drive access), and V16 (which removed hard drive access).

Edited November 19, 2019 by atrax27407

[+InsaneMultitasker]

There are two known bugs in V12 that were identified long ago by an astute user/programmer.  Alas, the text file containing the fixes is missing the crucial details, and there is no guarantee the surviving source code matches the version he fixed.   Tony's updates were based on the V11 EPROM image. 

[+9640News]

On 11/18/2019 at 8:11 PM, InsaneMultitasker said:

There are two known bugs in V12 that were identified long ago by an astute user/programmer.  Alas, the text file containing the fixes is missing the crucial details, and there is no guarantee the surviving source code matches the version he fixed.   Tony's updates were based on the V11 EPROM image. 

Was the V11 source ever available?

[+9640News]

I have another question as I am wanting to revisit an old project I once attempted.  Can someone show me a piece of assembly code with the CRU of the HFDC at >1000, that would turn on and show the RAM contents at >5400 for the first bank of a 32K memory block and the last bank of the 32K memory block?  I am not quite sure how to read the CRU relative address for 12-1A as defined below.

 

 

[+FarmerPotato]

5 hours ago, 9640News said:

I have another question as I am wanting to revisit an old project I once attempted.  Can someone show me a piece of assembly code with the CRU of the HFDC at >1000, that would turn on and show the RAM contents at >5400 for the first bank of a 32K memory block and the last bank of the 32K memory block?  I am not quite sure how to read the CRU relative address for 12-1A as defined below.

 

 

LDCR writes bits LSB first. It is saying that a 5 bit bank number begins with LSBit at 1012.

 

Since it’s less than 8 bits, LDCR takes from the MSB:

LI R12,>1012
LI R1,>1F00  set bank >1F
LDCR R1,5

 

The ROM page select bits appear to be in 2X format. Going MSB first. So these are equivalent:

LI R12,>1000
SBZ 3     MSBit in docs - zero
SBO 4     LSBit in docs - one

and

LI R12,>1006
LI R1,>0200   bit order reversed: one zero
LDCR R1,2

 

 

 

Edited September 28, 2022 by FarmerPotato

[+InsaneMultitasker]

46 minutes ago, 9640News said:

Was the V11 source ever available?

Not to my knowledge. The only version of the DSR source that I have seen is what I released from John Birdwell's MFM hard drive backup disks.  There may have been another release (same version) floating around, possibly from Mike, as I think I got the physical disks from him.  That was 30+years ago.. wow.  

 

Unfortunately, there were many code changes between the stable V11 and the unproven V12/V13. It would not be easy to disassemble V11 and reconstitute the source based on V12.  Although I started to do just this, I quickly realized I wasn't interested in another S-Rank project.

 

[+9640News]

1 hour ago, FarmerPotato said:

LDCR writes bits LSB first. It is saying that a 5 bit bank number begins with LSBit at 1012.

 

Since it’s less than 8 bits, LDCR takes from the MSB:

LI R12,>1012

LI R1,>1F00  set bank >1F

LDCR R1,5

 

The ROM page select bits appear to be in 2X format. Going MSB first. So these are equivalent:

LI R12,>1000

SBZ 3     MSBit in docs

SBO 4     LSBit in docs

and

LI R12,>1006

LI R1,>0200   bit order reversed

LDCR R1,2

 

Thanks for the feedback and example.

[+mizapf]

The MSB and LSB specifications were added by me when I created the HFDC PDF document from the scanned sources.