[sebhc] HDOS sysgen questions (and problems)

Lee Hart leeahart at earthlink.net
Tue Jan 9 08:24:58 CST 2007

From: Bob Shannon
>> Getting back to old computers once again, I tested the disk Mark kindly
>> sent. The machine 'seems' to boot, but I get gibberish on the console.
>> Typing seems to echo gibberish, sure looks like a baud rate issue to me.

I agree. Heath shipped their HDOS disks to auto-detect the console baud 
rate. You had to repeatedly type the space bar until HDOS figured out 
the baud rate. Once it did, the baud rate was saved on the disk, so you 
didn't have to do it again.

The Heath CP/M disks came configured for 9600 baud, but you could change 
them to anything you liked with the CONFIGUR utility.

In your case, it sounds like the disk you have has already been set for 
some baud rate. BUT, your H19 terminal's baud rate is set to some 

Stock, the H19 and H89 DIP switches were set for 9600 baud. But it was 
common to set them to 19200 baud as well. So, my guess is that you have 
a disk set for 9600 and H19 set for 19200 (or vice versa).

The easiest way to figure this out is to boot the system to the point 
where you are getting the gibberish. Then press OFFLINE ESC x L OFFLINE 
(the offline key should latch down the first time, then pop back up the 
second time). This sets the H19 baud rate to 9600. Type commands and see 
if it is now working.

If not, try OFFLINE ESC x M OFFLINE. This sets the H19 baud rate to 
19200 baud.

Once you know what baud rate the disk is set for, you can set the H19 
DIP switches (on the TLB) for the appropriate baud rate.
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in    --    Leonard Cohen
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net

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