[sebhc] New Heathkit H89 owner with many questions...

[Mark Garlanger]

Hi Bob,

   Welcome to the group. You'll find a large collection of
documentation and disk images in the library. These include many
versions of both HDOS and CP/M.

On 9/25/06, Bob Shannon <bshannon at tiac.net> wrote:
> Hello Heathkit fans,
>
> I've been collecting vintage computers for over 10 years, and I have a
> rather large collection of HP minicomputers
> and a few other odds and ends.
>
> Oh yeah, I have another Heathkit 'computer', sort of, I have a complete HERO
> 2000.
>
> I was just given a working, very clean H89 machine, with a single, worn,
> bootable floppy.
> I'm trying to get up to speed on this machine, but I have limited
> documentation.
>
> Here's what I know:
>
> This machine was used in the development of an array processor that was sold
> by Analogic Corp.
> Its been sitting in the office of one of the senior engineers that been with
> Analogic for decades.
>
> There are two half height floppy drives in the machine, and I have a single
> diskette.  The media
> is clearly soft-sectored, and shows visible wear on several tracks.  I'm in
> fear of loosing my
> only bootable diskette.
>
> The machine boots HDOS, and DIR shows the following results:
>
> NAME        EXT        SIZE        DATE
>
> MBASIC    ABS        77            9-JUL-85
> MDFAST    ABS        1            9-JUL-85
> MDSLOW    ABS        1            9-JUL-85
> SYSHELP    DOC        8            9-JUL-85
> SYSLOGO   CMD        1            27-JUN-86
> TEMPLATE    ASM        3         9-JUL-85
> TEMPLATE    CC          2            9-JUL-85
> VAX              ABS        1            9-JUL-85
>
> 8 FILES, USING 94 SECTORS (1800 FREE)
>
> No sysgen, not even a full distribution HDOS as far as I can tell.  I'm not
> at all sure
> that I even have enough there to copy the one disk I do have.
>

Probably not, BTW: HDOS 2.0 is not Y2K compliant...

> MBASIC runs, 1977 Microsoft basic!  WooHoo.  Is there any documentation for
> this on-line?  I cannot seem to recall how to save and load basic problems,
> but
> I have written a few 'hello world' type programs that run just fine.
>

Should be the same as the CP/M:

load "FILE.BAS"
and
save "FILE.BAS"

not sure about HDOS, but on the CP/M one, it's case-sensitive for both
loading and saving -  it'll lets you save "test.bas" and doesn't
convert it to uppercase for you. (BTW: Does anyone know how to delete
a file with lower-case characters in the filename under CP/M (or
directly from MBAS) ;-) ) .


> During the boot process some sort of modem device driver loads.
>
> Oh yes, the machine reports 56K of ram installed.  The past owner told me
> about
> the missing etch and being able to address more than 48K of ram.
>

If HDOS reports 56k, then you probably have 64k.

> I have not yet seen the interior of the machine, its sitting in my office at
> work (I also
> work at Analogic).  I'll be completing the paperwork maze to get this
> machine off
> the company books and back to my shop at home.
>
> Ok, question time...
>
> 1. Can anyone here send me any bootable media for this machine?
>

Unfortunately, I still don't have a working Soft-sectored controller
after more than 2 1/2 years of trying.

> 2. Is it possible to know what disk controller I have installed without
> opening
> the machine up?
>

If the soft-sectored disk boots, then you definitely have a
soft-sectored controller, there were a couple of 3rd party
manufacturers of soft-sectored controllers, so if you're asking about
that, you'll probably need to pop it open to find out.
It's fairly easy - There are two latches on each side, use a flat head
screw driver and pull them toward the front of the computer and lift,
the top should then flip back. You said it was an H89, if so, or Z89
and not the Z90, then it probably also has a hard-sectored controller
installed since that was standard (unless your company specifically
removed it). The system can supports up to 2 drive controllers.
If you can't identify something take a picture of it, and we should be
able to tell you exactly what you have.

> 3. Can I switch from HDOS to CP/M 2.2?
>

You should be able to. There was some 'ORG 0' modification required
for CP/M on older systems maybe the 'missing etch' that was mentioned
to you is the same thing. Since yours has 64k, I bet it can boot CP/M.

> 4. What is the most practical way to get software and data onto this
> machine?
>

Good question. I was able to find some hard-sectored disks and used a
serial cable along with Dwight's program to transfer images (all
available in the library). It works good, but unfortunately, I don't
have enough disks to store everything I want to.
With the soft-sectored controller, you should be able to find blank
media relatively easy and store much more per disk.


> 5. Is there some way to use an old PC with a 360K drive to write H89 media,
> or do I need
> to use some sort of serial loader?
>

I remember seeing some program for the PC that would read H89
soft-sectored disks. Not sure if it would write them. For
hard-sectored, it's definitely not possible at least with standard
hardware.

> 6. Is there any generic parallel interface option available?
>

Yes, there were 3rd-party Centronics Parallel port cards and I believe
Heath made one (H-89-11?) also.
I have a 3rd party (FBE) parallel interface card that I would gladly
trade you for the soft-sectored controller. I'll even throw in an
Epson MX-80.. and a hard-sectored controller if you needed it. ;-)


> 7. Can MBASIC perform character I/O to a H89 serial interface?
>

I've never tried but it should be since the terminal part of the H89
is actually connected to the CPU part by a serial interface. Also,
once you get an HDOS distribution, you'll have an Assembler.

> 8. I understand I cannot use SVD with my H89, (not hard sectored), is this
> correct?
>

Not sure, but according to his site, the SVD creator is currently not
filling any new orders. It says that he's taking this time to upgrade
the SVD, I don't remember what it said was going to be added though.

> 9. Would it be more practical for me if I had a hard sectored disk
> controller and SVD?
>

Hopefully there is one already inside your H89. And hopefully the new
SVD will be available soon.

> Here are my plans for the H89..
>
> First off, if I'm going to keep this thing, I think I'll replace the CRT and
> switch to a green
> phosphor.  The stock tube is perfectly servicable, but it does have very
> slight screen burn
> and re-tubing a Heathkit is a cakewalk.
>

Green was one of the options for the original H89 so it will still
look authentic.

> I'd love to be able to tie the H89 to one of my vintage minicomputers.  The
> H89 could
> serve as a combo console and mass storage system, either for one of my
> really old core
> memory HP's, or for my ultra-rare Imlac PDS-1.
>
> I'd need either a generic parallel interface, or I could build a serial to
> parallel interface dongle
> to drive the paper tape reader interface on an HP.
>

Apparently the other disk controllers for the H47 and H67 were just a
glorified parallel interface, and the real drive controller logic was
contained in the external boxes. Maybe you could use one of those.

> I could tie the H89 directly to the serial interface on the Imlac, but the
> Imlac itself is actually
> a smart terminal intended to tie into a larger (mainframe) system.  But I
> could store Imlac
> software on the H89, and write a program to send the images out the serial
> port to boot
> the Imlac.  It just seems a bit odd to have two machines that at least
> 'look' like terminals
> working together.  On the other hand, I would not need any parallel I/O for
> this.
>
> Any reccomendations?
>

Not really, the H89(s) are the only vintage PCs I have.

> Or should I keep using modern PC's to support vintage CPU's?
>

That seems the easiest option for now, until someone gets IDE or flash
or usb or some other cheap/current media working...

Mark
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