Bought an Vendex Headstart System Turbo 888 XTA

[luclodder]

Okay. This is my first post here on the forum.
Just bought a Vendex 888 XTA system with monochrome monitor.

Never had an XT system back in the days, i started with C64 which was followed by an Amiga 500 and later an A1200. The C64 and Amiga i still own. When the Amiga era ended i switched to pc's and build them myself. I started in the 386 era.
I never sold the C64 and Amiga 1200, however i did sell all my pc's. These day's I work with apple and some pc laptops with linux mint and windows 10 / 11 on them.
But... i want to collect some retro systems. I started with a relative cheap XT i found online. The case and the monitor aren't yellowed at all! I am stunned about the quality of the exterior. No scratched... just looks mint.

Although I expected problems with the Varta. So i opened it up. Screws were very tight. I guess it has never been opened. And yes... the varta was leaking. The RTC circuit is a bit damaged.

I desolderd the Varta and C43 and C44 (20pf ceramic) capacitors are dameged. I can easily replace them, got some 22 pf in stock here.
What do you guys think about the damage on the board itself?
And R7 seems to be missing (never soldered?)


Second question is if somebody has MS-DOS 3.3 5,25" diskettes to sell, coz the system came with no disks. I need something to boot.
Screen turned on and it looks for a bootdisk in drive A:

The schema of the RTC circuit is here -->
Page 107 (A-3)

https://minuszerodegrees.net/manuals/Vendex/Vendex%20Headstart%20Turbo-888-XT%20-%20Servicing%20Guide.pdf

 

[modem7]

Okay. This is my first post here on the forum.

Welcome to these forums.

I desolderd the Varta and C43 and C44 (20pf ceramic) capacitors are dameged. I can easily replace them, got some 22 pf in stock here.

You may discover that crystal Y2 is damaged as well. Time will tell.

What do you guys think about the damage on the board itself?

The printed circuit board (PCB). It is hard to tell from the photos. You can test suspect traces by using a multimeter.

And R7 seems to be missing (never soldered?)

Looking at the circuit diagram, the /CS pin to the RTC chip has a pull-up resistor at position R16. The circuit diagram shows that R7, if fitted, is there for when the motherboard is powered off, R7 'pulling' the /CS pin HIGH (specifically, to the battery voltage).
But I don't think it is required. For example, I own the RTC card shown at [here], a card that also uses a 58167 type RTC chip. On that card, the /CS pin of the 58167 does not connect to any resistor pin (only connecting to pin 6 of the 74LS08).

Second question is if somebody has MS-DOS 3.3 5,25" diskettes to sell, coz the system came with no disks. I need something to boot.

The 'Wanted' section of these forums would be a good section to post that question.

If you are in Australia, I can supply the disks.

Note, that like the IBM PC (IBM 5150) and IBM XT (IBM 5160), you may discover that if you connect up a 1.44M diskette drive, that you can boot/read 720K sized diskettes. Additional information is at [here].

 

[Ruud]

Second question is if somebody has MS-DOS 3.3 5,25" diskettes to sell, coz the system came with no disks. I need something to boot.
Screen turned on and it looks for a bootdisk in drive A:

I have them and you can get a copy. I already PMed you.

 

[gurby]

Note, that like the IBM PC (IBM 5150) and IBM XT (IBM 5160), you may discover that if you connect up a 1.44M diskette drive, that you can boot/read 720K sized diskettes. Additional information is at [here].

Hi @modem7 ,
Is this known to work with the Headstart Explorer? I also have one but the 720k diskdrive is broken. The diskdrive is hard to replace because it has a different connection than the regular drives....

 

[modem7]

Hi @modem7 ,
Is this known to work with the Headstart Explorer?

I don't keep a list, and so my answer is no. However, the likelihood of it working is very high. I have yet to hear someone report back to the forum that they tried it and it didn't work.

 

[gurby]

I doubt the IBM 5.25" diskette drive adapter will fit in the Headstart Explorer expansion bay due to its length.

In below topic you can find more details about the exact diskdrive which is in the HeadStart Explorer. Do you probably know of a replacement model with the same connection type? All Epson SMD-400 which I see online are from Amiga and those kinds and also have a 3 wire power cord while the Headstart Explorer SMD-400 only has the big connector with 34 pins.

https://forum.vcfed.org/index.php?threads/diskdrive-dd-720k-epson-smd-400-not-working-help.1238107/