Re: 9885 disc on 9825 machine - getting closer

Paul Berger

On 2017-04-17 9:17 AM, Jack Rubin wrote:

Ansgar - re the msus syntax, I don't think it's a bug - it's a feature that you allow more granular addressing, but it wasn't something I was familiar with on my older equipment. I started testing with an HP-85 and talked to the 9895 using msus :770 and :771. When I switched to HPDir, 770: didn't work but 707: did. That's when I realized you had added another addressing digit (that reflects 9845 usage?), thus 7070: and 7071:.
No the 9835/45 use a unique format like nearly every other HP system, it makes it fun switching between them. They use a letter to designate the drive type F=9885 H=9895, the first drive of a 9895 attached to a HPIB adapter with select code 7 and controller address of 7 would be ":H7,7,0" There are also short forms, for instance ":H" = ":H7,0,0"

- re DS vs SS disc/k (even HP goes back and forth on "disk" and "disc" spelling) - I've got the covers back on both drives but can the 9885 read both types? There are index LEDs for both disk types in the 9895 but not sure about the 9885.
The 9885 drive only has the one index sensor and is positioned for single sided media, the drive does however write the data in a double density format.

Craig and others - two questions - first, if I understand your answer, a properly initialized disk should load with the 98217 ROM only and does not require any use of the tape?
The tape utility was only required to write the boot straps onto the diskette, a "properly formatted" diskette for use with the 98217 ROM would need to include these bootstrap, the 98228A ROM does not require these bootstraps to be present. There is a image of the 98228 ROM and suggested electronics available in the file section for this group.

- maybe more fundamental, how do I determine if my ROM is in place and actually working? Again, the system test tape seems to be non-existent but I thought that typing reserved words such as 'drive' or 'cat' should get a D or F error rather than an 03 error. More generally, how do I determine if any ROM is in place and functional? Does typing a reserved word work as a quick functional test?
If the ROM is correctly installed and functional you should get an error other than 3. Beware of the 98218A ROM they have been sold on eBay as the diskette ROM for 9825 but they are really for 9831 (9825A hardware running BASIC) and will not work with the 9825 HPL OS.


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