Hello from Romania for Vintage Computer owners, users and everyone else

[isse]

I'm very happy to be a part of the Vintage Computer community.
I'm mainly a home computers collector ( 8bit Z80 based microcomputers). For now I have only a small collection of (9) computers: Sintez (russian made), Tim-S (romanian), Prae (romanian), 2 HC-91 (romanian) with IF1 interface (works with 3.5 FDD), 2 HC-91 without IF1, CIP-03 (romanian) and today's addtion, a Spectrum+ (UK i think). Still to come HC-2000 (romanian), Cobra (romanian) and other Z80 based stuff. Hopefully i will post some pictures with my stuff later on.
I also started some experiments with one of the Z80 machines (HC-91 w/o IF1). One of them is replacing the ROM chip with a flash chip so that i can modify when needed. So far i installed a 28 pin socket where the original ROM was and now i'm searching for a compatible flash memory. Later on i will try to add SD card and/or USB stick support for it (i saw that someone from NL already succeeded in that and i sure can use some information regarding the modifications. I'm a beginner regarding electronic stuff but willing to learn. That's all for now.
Happy to be here.

 

[Vint]

I've never heard of any of the computers in your collection, so I Googled a few of them. Sure would like to see pictures of your machines.
Yes the flash memory 'upgrading' for vintage machines is an exciting prospect. I was just looking at an SD card for my TRS-80 Model 100 under another post http://www.vintage-computer.com/vcforum/showthread.php?19103-SD-card-reader-for-Kaypro,
(post # eight) in the thread, here today. It's called the NADSbox - but when I saw the price, I fell off my stool! I'm sure it's worth it but I certainly couldn't afford it at $195. That's just not in my hobby range.
Anyway, there's something for every level of vintage computer hobbyists here - so Hi, and welcome to the forums

 

[isse]

Thank you very much Vint. Right now i'm still at work but when i get home i'll take some pictures and post them here along with a short description of each. I've already modified some of them so i could supply them 5V using an old PC AT power supply because i got most of them without power supply. Regarding the SD card project i will use the VDIP1 component (about 28$) along with a few other components that don't cost that much. If i am allowed i will also post the schematic and/or pictures i found regarding this. Now a little question. I have a bootrom chip from an old network card (Genius, i think) that has 28 pin as the ROM from my old test computer. I've also got a PCI 10M network card (Realtek rtl8029AS). This one has a bootrom socket and i intend to use it to write information on the bootrom chip (if that is possible). I also noticed that the bootrom chip has a UV windows so i guess that i cannot program it until it's erased. Am i right ?

 

[Dwight Elvey]

-snip---
I also noticed that the bootrom chip has a UV windows so i guess that i cannot program it until it's erased. Am i right ?

Hi
That is a regular EPROM, not a Flash. You'll need to erase it with UV and use
a programmer to program it.
You need to look for a regular Flash chip. Most of the newer ones won't
work as well because they have multiplexed address or the reduced pin
configurations. You need to look for one of the earier ones. Many of these
have a protected portion that you can but basic boot and programming
code in. Most of these earlier ones require +12v for programming but
this is a generally available voltage in most machines.
Dwight

 

[digger]

Welcome to the forum, isse!

You bring a lot of new lore to the table here with all of that mysterious vintage hardware from behind the Iron Curtain.

Have fun here, and good luck with all of your interesting projects!

 

[isse]

Hi
That is a regular EPROM, not a Flash. You'll need to erase it with UV and use
a programmer to program it.
You need to look for a regular Flash chip. Most of the newer ones won't
work as well because they have multiplexed address or the reduced pin
configurations. You need to look for one of the earier ones. Many of these
have a protected portion that you can but basic boot and programming
code in. Most of these earlier ones require +12v for programming but
this is a generally available voltage in most machines.
Dwight

Hello Dwight, first of all i thank you for the information provided. I still have to learn about this stuff (multiplexed address) you talk about. As I said earlier, someone already made this modification by soldering the flash memory (32 pin, 12V for programming, i think it's 28xxx series) on board and the original 28 pin ROM on top of the flash memory with some minor modification (some wires soldered to another chips). I will dig into this more later on.

Welcome to the forum, isse!

You bring a lot of new lore to the table here with all of that mysterious vintage hardware from behind the Iron Curtain.

Have fun here, and good luck with all of your interesting projects!

Digger, thank you very much for the good wishes, I pretty sure I will find some answers here in this big community regarding my experiments. Now i will try to post some pictures i've just made even if in my country it's almost 0'o'clock and i'm a little tired.

LE: First picture presents the inside of a HC-91 computer without the IF1 interface. The second picture presents the microcomputer named CIP-03 (03 means it's the third variant, there is also a 4'th generation that has a 3.5 FDD built-in but this generation is sort of rare). The third picture shows the Tim-S computer, this is also a rare machine (this one has a different keyboard unlike the later models). The fourth picture shows a HC-91 (50 keys version) with the IF1 interface. The last picture presents Prae (also a rare machine). From what i've read this is not a Spectrum clone but an original design.

 

[isse]

More pictures

More pictures

More pictures...

LE: First picture shows the 40 keys version of HC-91 with IF1, the second picture shows all four sinclair clones (HC-91), third picture presents Prae (power supply built in), next picture shows an old russian tape recorder/player used by me on the spectrum computers and the last picture shows the CIP-03, Tim-S and Prae.

 

[isse]

Even more pictures

Even more pictures

I'm sorry i don't know how i can add more than 5 pictures in post...

LE: First is presented the back of the Sintez computer, next the back of the Spectrum+ can be seen, the third picture shows an old russian tape player/recorder and the original box of the Spectrum+. In the next picture the back of the Sintez along with the Spectrum+ and last can be seen the Spectrum+ manual with an old HC-85 (i do not own this model as it is very rare) technical manual.

 

[isse]

Last pictures...

Last pictures...

for now...

LE: First picture shows Sintez (russian spectrum clone), second picture ZX Spectrum+ and Sintez (notice the similarities), third picture shows the inside of Sintez computer, next the Spectrum+ is presented and last picture shows the back-cover of the Z80 Assembly book described in the next post.

 

[isse]

RE: Last pictures

RE: Last pictures

for now...

Really last pictures

L.E.: The pages from the third picture are from a book about Z80 assembly language called "The wonderful world of Home Computer" (Minunata lume a HC-ului), first picture shos the backside of the Prae computer, the second picture displays the backside difference between HC-91 w/o IF1 (top) and HC-91 with IF1 (bottom), next picture presents all the computers togeter and the last picture shows the back of the Tim-S computer.

 

[isse]

(E)EPROM and/or Flash programming

(E)EPROM and/or Flash programming

Hello again, i was thinking about buying a Willem Pro 4 universal programmer to help me on my Flash/Rom experiments. Does any of you have any experience with this tool or should i look for something else ?

 

[lending]

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[Chuck(G)]

Hello again, i was thinking about buying a Willem Pro 4 universal programmer to help me on my Flash/Rom experiments. Does any of you have any experience with this tool or should i look for something else ?

They work pretty well for most common things. If you've got some really vintage EPROMs requiring special supply voltages, such as 1702A or 2708, it's not the tool for you.

Please note that "Willem" is just a name for a circuit design and not a brand. So the quality on the programmers being sold can vary quite a bit. Be sure to get one that's well-made.

 

[isse]

Hello Chuck and thank you for the info. In my country i found this model (i'm just e begginer regarding the EPROMs programming) Willem Pro4 ISP

 

[Chuck(G)]

That looks better than many of the ones offered on eBay, which are usually just bare circuit boards.

 

[isse]

Latest news: I've boght the Willem Pro 4 programmer but the user manual is in Polish i don't understand anything from it. I hope i can find an english manual somewhere on the internet. Next i'll search for the 28C256-150 chip (EEPROM 5V 32Kx8 150N DIP28 RoHS) as this might be the right choice for my experiment. It is presented as replacement for AT28C256, ST28C256-150, ST28C256-250. I'll post an update as soon as any progress is being made.

LE: I've just added a "new" item on my vintage computer collection: Schneider EuroPC. Don't know if it'll start but i'll check it later tonight. It also came with a monochrome monitor that i hope i can connect to my Spectrum clone computers.

 

[isse]

Formox CM-312

Formox CM-312

Hello again, has any of you encountered an EGA color monitor named Formox CM312 ? It looks like there is no information regarding this monitor anywhere and i would need some schematics of it

 

[Erik]

Welcome aboard! Very nice stuff!

Enjoy!

 

[isse]

Update

Update

Thank you, Erik . I have received my EEPROM's and after looking into the datasheets i've noticed that there is a small difference between 27C256 and 28C256. Two pins are in different locations. I will try to find a workaround in order to succeed replacing the 27 with the 28 EEPROM (luckly i've ordered two of them just to have a spare in case i'll need one).

Regarding vintage stuff (related to x86 architecture) i have about five 6x86 Cyrix processors, three socket 7 motherboards (1x Via chipset, 2x intel chipset). I also have the 5.25'' FDD from my old 286 computer and a bunch of 5.25'' floppy disks. Not so vintage stuff is a Compaq Deskpro 4000 (P2-266 MHz, 64MB ram, Matrox PCI videocard) and a quad P2-Xeon 450 MHz server that has a problem with the memory card board that i hope i will fix soon.

Now that we're in the Introductions section i must say that i also like motorbikes (for now I own a 600 cc Honda CBR 600F and a two cylinder 350cc Jupiter 4 russian motorcycle).

As for connecting my spectrums to the EGA monitor i will make a custom cable for this even if it works (the characters seem to leave a trace in the right part where the char appears) because there are some things different on the HC-91 and monitor connectors (for example, the EGA expects the Ground pin to be pin 1 and the HC-91 connector has Ground on pin 2). Maybe when the connections are made properly, the text will be displayed sharper.

 

[isse]

Hello people! It's been a long time since i've posted here but i've been busy moving into a new home. My collection hasn't changed much during this time but i have found the memory expansion board needed in order to revive the old quad pentium 2 xeon server. The problem is that the board can be found only on ebay (USA sellers are not willing to send to Romania and I can understand that because of what happened lately with romanian customers). That's all the news i've got so far. Now i have to convince the ebay seller that i'm a trustworthy customer.