Author Topic: N00b alert! (Read 7484 times)

emptiness · « **on:** 2020.June.19. 09:55:09 »

I grew up with the ZX Spectrum 48K and was never able to get hold of an Enterprise in the 1980s. I'm now a software engineer looking to get back into Z80 assembler and have been playing with the RC2014 (https://rc2014.co.uk/)

I just bought an Enterprise 64 from a seller who seems to have several boxed computers which he's selling as new. Obligatory photo included

Everything seems to be there apart from the BASIC cartridge. The seller claims that they never had this, but given the box contains a BASIC programming manual this seems suspicious to me.

Does anyone happen to know if Enterprises were ever shipped without BASIC?

I've ordered a SCART cable from http://retrocables.es/tienda/index.php?id_product=48&controller=product&id_lang=1 and am attempting to control my patience so I can see if the Enterprise is working ok? I'm also hoping to buy an SDcard adaptor from Szorg.

While going through my stash of old hardware I also found what looks to be an Enterprise motherboard. I'm not sure how I got hold of it or if it works but it would be kind of fun to see if I can get it working and build a new case and keyboard for it.

Anyway, I was really pleased to find this forum. Great to see there is still an active community around the Enterprise. It feels like I've been given a second chance after missing out in the 80s'. I beg forgiveness in advance for any dumb questions I might ask while getting used to this new platform.

Zozosoft · « **Reply #1 on:** 2020.June.19. 10:26:38 »

Welcom here!

Quote from: emptiness on 2020.June.19. 09:55:09

I just bought an Enterprise 64 from a seller who seems to have several boxed computers which he's selling as new. Obligatory photo included

Can I ask another one with the Serial Number? For the big EP statistics.

Quote

Does anyone happen to know if Enterprises were ever shipped without BASIC?

No. But easy to lost it under ~35 years...
Anyway I often see standalone cartridges at same Egyptian seller...

1) you can also load machine code programs from the WP, don't need a BASIC for playing most of games.
2) best way to get BASIC: upgrade the onboard ROM to EXOS 2.4, which have a built in. One 27C512 EPROM needed, and solder one wire for the A15 address line.
This is ROM upgrade also highly recommended, because many of programs compatible only with EXOS 2.1+ but the EP64 just come with earlier 2.0

Quote

and am attempting to control my patience so I can see if the Enterprise is working ok?

You can also try it without display. Power on, wait few secs (memory test), then need to hears key click from the internal speaker when pressing keys. If this is done, then machine mostly working.

Quote

I'm also hoping to buy an SDcard adaptor from Szorg.

It is also including the BASIC in the default ROM pack. Then not need to look about cartidge, even if not upgrading the onboard ROM.
If do the ROM upgrade, then you can have free 32K RAM space in the SD cartridge, you can install other utility or programing languages.

Quote

I'm not sure how I got hold of it or if it works

For a first look I recommend replace the Philips electrolytic capacitors. The C9 are the most critical. If it is dried out then kill the TR2 transistor in the internal 12V circuit, then the video circuits don't get the 12V supply.
It is also possible this is happened with that board many years ago.
Later boards with a non Philips capacitors less problematic.

Another common failure (at unknow dead boards) when the machine tried with a wrong polarity PSU. Then the board look total dead, power LED still remain off. For a repair need to replace the two 7805, TR2 (BC337), and LM386 (amplifier for internal speaker, directly connected to the 9V). It is can be repaired less than 10 minutes

gflorez · « **Reply #2 on:** 2020.June.19. 12:17:11 »

This is what we know about the Egyptian Enterprises:

Quote from: Werner Lindner(Former director of Enterprise Computers GMB):
"Egypt:
The Egypt importer was Computer Technical Co. in Cairo. The founder and M.D. was Mr. Nabil Lashine. He had already bought about 500 ENTERPRISE 64k machines from England. He imported them to Egypt and sold them as electronic typewriters to other companies. He was not interested in games or other ancillaries, because he couldn't sell them (nobody in Egypt could afford a home computer for private purposes at that time). He made his own software for the computer and did the green keyboard print by himself. He bought additional 64k machines from us, but there was only appr. one shipment per year and not more than 150 machines (25 boxes á 6 computers). He also got appr. 500 empty cartridges from us. He always payed with monthly cheques. Sometimes it took long to get the money, but he was very reliable. His last order was in 1993, last contact to him in 1994. At this time his company was in big trouble and his bank had the hands on his remaining stock of EC machines. I've never heard of him afterwards, but I still have a complete set of printed keys, that he gave me while he was visiting us in Munich. All in all I think that 4000 units is too much - I personally know only about 1500 units, incl. the machines from England (but maybe Latchu has sold something to him directly)."

Probably these new Enterprise64s without Arab keys that are actually being sold are some stock that have been keep retained a lot of years by the Bank.

Some other buyers of this batch of Egypt EP64s have got the original Basic cartridge included.

Every now and then surface some used EP64 with the Arab keyboard from Egypt. A Spanish friend of mine have one of these.

dangerman · « **Reply #3 on:** 2020.June.19. 12:30:06 »

Welcome!

Where are you from? If you can find an old PAL TV with analogue tuner in your country, then you shouldn't need a monitor cable, you can connect to an old TV. But of course, a monitor will give you a much better picture.

Also, if you hard wire an old keyboard (time consuming but I know people who've done it), then that's all you need to turn your motherboard into a fully functional enterprise.

Zozosoft · « **Reply #4 on:** 2020.June.19. 12:51:24 »

Quote from: dangerman on 2020.June.19. 12:30:06

Also, if you hard wire an old keyboard (time consuming but I know people who've done it), then that's all you need to turn your motherboard into a fully functional enterprise.

Yes

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emptiness · « **Reply #5 on:** 2020.June.19. 13:37:43 »

Quote from: Zozosoft on 2020.June.19. 10:26:38

Welcom here!Can I ask another one with the Serial Number? For the big EP statistics.

Happy to oblige!

Quote from: Zozosoft on 2020.June.19. 10:26:38

1) you can also load machine code programs from the WP, don't need a BASIC for playing most of games.
2) best way to get BASIC: upgrade the onboard ROM to EXOS 2.4, which have a built in. One 27C512 EPROM needed, and solder one wire for the A15 address line.
This is ROM upgrade also highly recommended, because many of programs compatible only with EXOS 2.1+ but the EP64 just come with earlier 2.0

Great to know. I'll certainly do that.

Thanks for all the other information too. That's going to be a great help testing both machines and getting them to a working state.

emptiness · « **Reply #6 on:** 2020.June.19. 13:42:17 »

Quote from: dangerman on 2020.June.19. 12:30:06

Where are you from? If you can find an old PAL TV with analogue tuner in your country, then you shouldn't need a monitor cable, you can connect to an old TV. But of course, a monitor will give you a much better picture.

I'm in London, sadly I don't have a TV with an analogue tuner for some years.

Quote from: dangerman on 2020.June.19. 12:30:06

Also, if you hard wire an old keyboard (time consuming but I know people who've done it), then that's all you need to turn your motherboard into a fully functional enterprise.

Oh man, I am definitely going to do that!

Rasputnik · « **Reply #7 on:** 2022.May.14. 20:16:54 »

Quote from: Zozosoft on 2020.June.19. 10:26:38

2) best way to get BASIC: upgrade the onboard ROM to EXOS 2.4, which have a built in. One 27C512 EPROM needed, and solder one wire for the A15 address line.
This is ROM upgrade also highly recommended, because many of programs compatible only with EXOS 2.1+ but the EP64 just come with earlier 2.0
You can also try it without display. Power on, wait few secs (memory test), then need to hears key click from the internal speaker when pressing keys. If this is done, then machine mostly working.
It is also including the BASIC in the default ROM pack. Then not need to look about cartidge, even if not upgrading the onboard ROM.
If do the ROM upgrade, then you can have free 32K RAM space in the SD cartridge, you can install other utility or programing languages.

Hi,

I'm a NOOB myself, so I thought it fine to post in this thread, that also touches on my subject. I wanted to make an easy and more complete guide for ROM upgrade and GND patching, so there wouldn't be a need to dig around in long threads not directly clear on this subject.

I've gathered the info mainly from enterpriseforever.com, in regard of your (Zozosoft) info on the upgrade of the ROM to include BASIC and your mention of the GND patch of 64 machines.

Can you verify (see attachment below), that I've gotten everything correct? Especially the point about removing the connection from ROM PIN1 to the mainboard ROM socket, and only connect to an A15 address point, since it's not mentioned anywhere I can find on Enterpriseforever. As known: PIN1 on 27C256 is Vcc and on 27C512 it's A15, which I would think shouldn't be connected to both SC and A15 at the same time (?).

gflorez · « **Reply #8 on:** 2022.May.14. 23:49:08 »

I think, but may be wrong, that pin 1 is set to +5v because then, on a 64KB ROM/EPROM, only one of the two 32KB banks would be used(fixed to the one with information), it would work exactly the same like a 32KB ROM/EPROM.

On the other side, if A15 is joined to +5v..... it could be dangerous, because it would produce a shortcut when Nick sets the signal to GND.

Rasputnik · « **Reply #9 on:** 2022.May.15. 01:18:44 »

Quote from: gflorez on 2022.May.14. 23:49:08

I think, but may be wrong, that pin 1 is set to +5v because then, on a 64KB ROM/EPROM, only one of the two 32KB banks would be used(fixed to the one with information), it would work exactly the same like a 32KB ROM/EPROM.

On the other side, if A15 is joined to +5v..... it could be dangerous, because it would produce a shortcut when Nick sets the signal to GND.

Thanks @gflorez, I think you're right.
BTW I made a type-o, Pin1 is Vpp not Vcc on 27C256, and I see now that 27C512 takes that through Pin22. So, I guess, Pin1 on 27C512 should be bent up or cut short as I thought.
Well, when I get my Enterprise, I'll test it.

Dr.OG · « **Reply #10 on:** 2022.May.15. 04:35:53 »

Quote from: Rasputnik on 2022.May.14. 20:16:54

...
Can you verify (see attachment below), that I've gotten everything correct? Especially the point about removing the connection from ROM PIN1 to the mainboard ROM socket, and only connect to an A15 address point, since it's not mentioned anywhere I can find on Enterpriseforever. As known: PIN1 on 27C256 is Vcc and on 27C512 it's A15, which I would think shouldn't be connected to both SC and A15 at the same time (?).

At the bottom of the webpage linked below you find a detailed description with pictures about upgrading EXOS ROM (U2):
http://www.ep128.hu/Ep_Util/Exos.htm
It's in Hungarian, but Google translate may help.
A15 should be taken from leg 17 of U6 IC.
I tried it myself some weeks ago, and works perfectly.
Regards: Gábor

Rasputnik · « **Reply #11 on:** 2022.May.15. 15:23:40 »

Quote from: Dr.OG on 2022.May.15. 04:35:53

At the bottom of the webpage linked below you find a detailed description with pictures about upgrading EXOS ROM (U2):
http://www.ep128.hu/Ep_Util/Exos.htm

Thanks @Dr.OG, I believe that's all the info I needed. I missed that one, cheers.

I think though, that I'll opt for a less destructive PIN1 solution. It seems harsh to physically break the trace on the PCB just to be able to solder a wire to the A15 from underneath the socket/PCB. It seems simpler to just bend up the Pin on the EPROM and solder (or Female Dupont) from there. Also in case I want to go back to original specs, like if selling on to a purist.

Quote from: Dr.OG on 2022.May.15. 04:35:53

A15 should be taken from leg 17 of U6 IC.

The U6 is closest, but a little fiddly (I'm a novice solder), and since I'm making my own RAM upgrade, I'll just take a Dupont to that PCB's A15.

Thanks again, nice

Rasputnik · « **Reply #12 on:** 2022.May.15. 16:27:10 »

Quote from: gflorez on 2022.May.14. 23:49:08

I think, but may be wrong, that pin 1 is set to +5v...
... if A15 is joined to +5v..... it could be dangerous, because it would produce a shortcut when Nick sets the signal to GND.

Yes, it seems to me that PIN1 (Vpp: Programming Voltage) and PIN28 (Vcc: Power Supply Voltage) are bridged on the PCB of the EP64. Wouldn't hurt the 27C256, but would make trouble on the 27C512.

Author Topic: N00b alert! (Read 7484 times)

emptiness

N00b alert!

Zozosoft

Re: N00b alert!

gflorez

Re: N00b alert!

dangerman

Re: N00b alert!

Zozosoft

Re: N00b alert!

emptiness

Re: N00b alert!

emptiness

Re: N00b alert!

Rasputnik

Re: N00b alert!

gflorez

Re: N00b alert!

Rasputnik

Re: N00b alert!

Dr.OG

Re: N00b alert!

Rasputnik

Re: N00b alert!

Rasputnik

Re: N00b alert!