[Simh] PDP-10 Home Block and KS10 Boot Code

[Cory Smelosky]

On Fri, 29 May 2015, Rob Doyle wrote:

>
> I was looking at the KS10 boot code in SIMH.
>
> The boot code looks for the Primary Home Block in disk block 1 and Secondary 
> Home Block in disk block 8.
>
> /* movei 2,10    ; blk #10 */
> /* jsp 17,rdbl   ; read    */
> /* movs 3,1000   ; id word */
> /* caie 3,sixbit /HOM/     */
>
> It looks to me like the Secondary Home Block is 10 (decimal)
> not 10 (octal). I see it at offset 10240 (decimal) in the disk image.
>

2400/   HOM
2401/   USER0
2402/
2403/   ______
2404/   USER

I also see it at 2400 octal

> Is the SIMH boot code correct?
>
> I'm guessing that it never fails over to the secondary home block so
> nobody ever noticed.
>

File: dskb:/u/p
[Patching structure DSKB]

200/   HRLI 17,0(15)   $6T
201/   DSKB0
200/   HOM      "/WOM/
201/   DSKB0    "/MUPPET/
203/            ^Z

% RPA0 first HOM block consistency error
Startup option:



> Rob.

-- 
Cory Smelosky
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