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Hello ...

mbbrutman

Associate Cat Herder
Staff member
Joined
May 3, 2003
Messages
6,408
This looks like a great group of people - nice diverse interests, and good vintage hardware.

I'm not much of a collector - no room and not enough time. So I choose to delve deep into my favorite machine, the IBM PCjr. Owning and loving a PCjr is close to being a member in a cult. Anything that was easy to do on a standard PC or clone is a pain on the Jr, which makes it so interesting.

http://mail.magnaspeed.net/~mbbrutman/PCjr/pcjr.html

Besides the PCjr, my other machines are:

Original IBM PC 5150 with first revision BIOS. This machine can't use a VGA, EGA or any other card with BIOS because it doesn't know to scan for BIOS extensions. The BIOS also has a bug that limits the reported memory to 544KB.

Original IBM PC AT 5170. This machine has a 386 motherboard in it and some other nasty upgrades, however I have all of the original parts. That includes the famous Seagate ST-225 hard drive.

Timex Sinclair 1000. My first computer ever. I have the 16K RAM expansion and the thermal printer. This is a machine I'd like to do more with.


The older machines are great hobbyist machines because it's usually TTL logic, well known processors, and slow enough speeds such that modifications and debugging are not impossible. I'm a programmer, and programming on these things is easy.

Favorite languages: Turbo C++ for DOS. This can generate code for my older machines. Turbo Pascal 3.0, which runs directly on my older machines. Zbasic, also for the older machines. And I'm learning assembler so I can be really dangerous. :)

Regards,
Mike
 
Welcome!

Welcome!

Hello Mike and Welcome to the VC Forum!

I don't have a PCjr in my collection (yet) but I've been hoping to add one someday. I do have the first few issues of Jr. and PCjr magazine and I remember when it was introduced.

I've also got an original IBM PC with BIOS 1.00 and DOS 1.00! The BASIC in that version of DOS had a floating point error that was famous in the day.

The Seagate ST-225 in your AT is nice to have. The original drive shipped with the AT was made by Computer Memories Inc. and has a "sad" story. When IBM came along and contracted with CMI for the drives they basically increased CMIs production tenfold or more. The result was a run of drives that were poorly built, poorly tested and insanely unreliable. At one point PC Magazine published an article that concluded that anyone with a CMI drive had best replace it because it WILL fail soon.

One of the replacement drive companies pulled a great publicity stunt. They gave a rebate for every CMI drive turned in and, once they had collected enough, dumped them (legally) off of the coast of Boca Raton FL, right in front of the IBM plant, to create an artificial reef.

Anyway, I'm rambling.

Welcome aboard!

Erik
 
The reliability problems with the CMI drives made for a black eye on IBM, and destroyed CMI as a company. I've never even seen a CMI drive. They truly were victims of their own success.

On the other hand, the Seagate drive is a classic. Crude and slow, but still working 20 years later. So many of the MFM drives are dead - they had a five year life expectancy. Mine still gets fairly good use - I have a Central Point Option Board in the AT, and the diskette images go to the Seagate, then later to a CD-R.

Seagate is just a great company, period. IBM invented the hard drive and the floppy drive. Alan Shugart worked on the design of the floppy disk at IBM, and later started his own company Shugart Associates, which later became Seagate. Besides giving us the floppy drive, Alan Shugart indirectly gave us great hard drives, the SCSI specification, etc.

Now I'm rambling ..
 
Hi Mbbrutman.I have 4 I.B.M. Pc's and 4 XT's .However all of my ibm Pc's
are the later revision board b type.
I saw that you had a Timex Sinclair 1000.I had one of these then later bought the TS 2068 Color computer before Timex Quit.I used to write
a lot of basic programs on this machine.I even spent a couple of months in 1984 making a 32k basic program that computed the ballistic flight paths of Amatuer Rockets (up to 4 stages)with 4 different atmospheric models,variable gravity,thrust curves,changing atmospheric density,temperature,pressure,mach force,hypersonic similarity etc on the TS2068.
Later I even found another TS2068 in a thrift store.There is a Web site called Planet Sinclair that shows all of Sir Clive Sinclair's machines.
 
Re: Hello ...

"mbbrutman" wrote in message:

> This looks like a great group of people - nice diverse interests, and
> good vintage hardware.

Welcome Mike,

> I'm not much of a collector - no room and not enough time. So
> I choose to delve deep into my favorite machine, the IBM PCjr.
> Owning and loving a PCjr is close to being a member in a cult.
> Anything that was easy to do on a standard PC or clone is a pain
> on the Jr, which makes it so interesting.

I was just wonderning if you're familar with this site:
http://www.micro-zone.com/
I think it might be an interesting site for anyone who has a
PCJr! :)

<snip!>

Cheers.
 
Re: Hello ...

mbbrutman said:
...Anything that was easy to do on a standard PC or clone is a pain on the Jr, which makes it so interesting.

That's funny, I got into Apple II's for much the same reason... I can spend a whole day messing about with something that would take 30 seconds to do on a newer Mac or PC, but it's the challenge and sense of accomplishment that make it so rewarding. Or maybe I'm just a masochist ;-)
 
Jon,

I never got into my Timex enough - I was too young to understand the potential of it. (I was 12 at the time.) BASIC was cool, but the machine could be much more. As limited as a 16K machine seems, there was an incredible amount that you could do with it. (And I will get back to it eventually.)

First off, it's a Z80. The Z80 is the single most popular CPU in the universe. There is a lot you can do with that puppy. Did you know it had two complete register sets in it? Pretty advanced for that era.

Next, there are the hardware mods. Getting up to 64K memory (some of it being ROM) . There were serial ports, stringy floppies, graphics cards, and all sorts of wonderful things built for these machines. Even something simple like a better keyboard would be nice. I never had these toys, but now I'm dangerous enough to build them.

In short, it's a great machine to explore. Simple enough to get your hands around.

Which Sinclar was the 2068 equivalent to?


Mike
 
CPM User,

Yeah, I know a little bit about that site:

- I inspired Brian to get back into Jrs.
- I've worked with Brian on recreating some of the ancient mods, including the bi-directional parallel port, the Dallas Semi clock chip, etc.
- I'm a moderator on that site.
- I'm chatting with Brian online right now! :)


Mike
 
Luddite,

Apple IIs are another great machine - they are the first PCs I ever touched. I couldn't afford anything like that back then, and by the time I was able to afford a machine, I went IBM. The 8088 based machines seemed to have more life in them than the Apple II series.

I still remember doing POKE commands to affect the behavior of the machine in strange ways. Poke 1012,0 disabled the RESET button or something like that ...

Yes, there is romance in doing things the hard way. A good Apple II+ would have maybe 48K of memory, a disk drive, and only uppercase letters. Yet the machines were so versatile. I remember having a choice between good old Integer BASIC and AppleSoft - imagine trying to use a dialect of BASIC now that didn't know about floating point numbers? Hard to imagine ...

Long live the Woz!
 
Hi mbbrutman.The TS2068 was the American version of the Sinclair Spectrum,except it had a 24k Rom rather than the 16K Rom of the Spectrum.You know it was a big shame but I saw a PCjr in the Original
box at a thrift store but didn't pick it up.Then again I didn't pick up a Apple III which now I know to be rarer than a LISA.
 
"mbbrutman" wrote in message:

> Yeah, I know a little bit about that site:

> - I inspired Brian to get back into Jrs.
> - I've worked with Brian on recreating some of the ancient
> mods, including the bi-directional parallel port, the Dallas Semi
> clock chip, etc.
> - I'm a moderator on that site.
> - I'm chatting with Brian online right now! :)

Oh well, that's good to hear! :)

Cheers.
 
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