consi@athena.mit.edu (Thomas R Consi) (03/21/91)
This message is empty.
consi@athena.mit.edu (Thomas R Consi) (03/22/91)
I am in the process of rejuvenating my Color Computer II and I have some questions about adding double sided double density drives: 1. I have some 360K drives from an old Leading Edge clone, they are made by Toshiba, model # FDD5425A0N. There is a a 9 pin jumper block on the drive (9 pairs of pins) labeled: TM, L1, LD, HM, HD, D4, D3, D2, D1 Does someone know what these pins do? The D4 to D1 pins are obviously the drive selects but what are the other ones? 2. I read somewhere (I think in an issue of the Rainbow) that the second drive (/D1) should be set so the disk motor always spins even if /D0 is selected. Is this correct and if so, why? By experimentation I put jumpers on pins TM, LD, HD and D2 (for drive /D1) and obtained the desired behavior. Is this a good jumper configuration? 3. Has anybody ever ROMed OS-9 (I guess the kernal, the CMDS directory and a BOOT file of some sort) and put the ROM in the COCO disk controller so the machine boots to OS-9 like it currently does to the BASIC interpreter? Any help would be appreciated. Tom Consi
kdarling@hobbes.ncsu.edu (Kevin Darling) (03/22/91)
>1. I have some 360K drives from an old Leading Edge clone, they are >made by Toshiba, model # FDD5425A0N. There is a a 9 pin jumper block >on the drive (9 pairs of pins) labeled: > TM, L1, LD, HM, HD, D4, D3, D2, D1 >Does someone know what these pins do? The D4 to D1 pins are obviously >the drive selects but what are the other ones? A good guess would be: TM is to enable the termination resistors; do this for last drive on the cable. L1/LD control when the LED is lit; experiment to taste. HM/HD would be headload on motor/drive select (altho usually HD is called HS), but I'd set it for HM nevertheless: >2. I read somewhere (I think in an issue of the Rainbow) that the second >drive (/D1) should be set so the disk motor always spins even if /D0 is >selected. Is this correct and if so, why? For the same reason you'd want the head-load on motor select... all CoCo drivers _expect_ that if one drive is powered up and ready, then all are. If they actually aren't, you can get r/w errors without knowing it. Cause: the drivers will send step-pulses to the drive, expecting it to be ready. It's not because it's still spinning up, and so most or all of the step commands get ignored. Ouch, you read/write to the wrong track. >3. Has anybody ever ROMed OS-9 (I guess the kernal, the CMDS directory and >a BOOT file of some sort) and put the ROM in the COCO disk controller so >the machine boots to OS-9 like it currently does to the BASIC interpreter? A very few may have done that for L-I. Most people only have their ROM autoboot OS9 from disk on powerup, tho... as they often add new modules. best - kevin <kdarling@catt.ncsu.edu>
vodall@hpfcso.FC.HP.COM (Bill Vodall) (03/23/91)
/ hpfcso:comp.sys.m6809 / consi@athena.mit.edu (Thomas R Consi) / 9:00 am Mar 21, 1991 / 3. Has anybody ever ROMed OS-9 (I guess the kernal, the CMDS directory and a BOOT file of some sort) and put the ROM in the COCO disk controller so the machine boots to OS-9 like it currently does to the BASIC interpreter? Tom Consi ---------- I've wanted to do something similar for a long time. One of these days I'll get caught up with all the other projects and get some free time to try this. I'd sure be interested in the details if anybody else has already done it. Bill