Year 1978/9
CPU 1 or 2 MHz Z80
Register size 8 bits
Installed RAM 2 kB (about 850 bytes for user)
Maximum RAM 2 kB (on board)
Installed ROM 1 kB (2kB with extended monitor)
Interfaces RS232, RF out, TTY, PIO lines
Storage Cassette 300baud
Case style Single board Computer (uncased)
Languages Z80 machine code + monitor


Year 1979/80
CPU 2 or 4 MHz Z80A
Register size 8 bits
Installed RAM 10 kB (nearly 9k for user)
Maximum RAM 32 kB (and/or ROM in selectable sockets on board)
Installed ROM 10 kB (including BASIC)
Interfaces RS232, Video out, RF out, TTY, PIO lines
Storage Cassette 300/1200 baud Kansas city
Case style Single board Computer (uncased)
Languages Z80 machine code + monitor and 8k Microsoft BASIC in ROM


Year 1982
CPU 4 MHz Z80
Register size 8 bits
Installed RAM 48 kB typ
Maximum RAM depends on expansion cards
Installed ROM 2k monitor + 8k BASIC – possibly others
Interfaces RS232, Video out, RF out, TTY
Graphics 40×25 text
80×25 text
320×256 8 colours
640×256 3 colours
Storage Cassette 300/1200 baud Kansas city with optionfor 1 or 2 320k 5.25inch floppy disk drives

using either CPM 2.2 or NAS DOS operating systems

Case style Keyboard/computer + monitor
Languages Z80 machine code + monitor and 8k Microsoft BASIC in ROM

Actually a cased Nascom-2 with a built-in power supply, bus and keyboard!


13 Responses to “Nascom”

  1. 1 Les Pickstock 02/10/2014 at 8:38 pm

    Old Nascom user..
    Can I email you?

  2. 3 Charlie 07/02/2015 at 4:02 pm

    Interesting blog. I had(have? I think it’s in my ex’s loft) a Nascom-2, on which I programmed geophysical stuff in BASIC and Pascal. You could load the Pascal compiler from tape. I also designed built an 80-bus serial comms board, hooked it up to an acoustic modem and used it as a remote terminal to a VAX 11/730 minicomputer in Croydon (from London W4). Happy days!

  3. 4 Adrian 06/06/2017 at 4:46 pm

    I have just donated my Nascom3 to the National Museum of Computing. I will be delivering it on Sunday next.june 11 2017.

    • 5 Mick 06/06/2017 at 7:45 pm

      This is something that I wish I’d seen. 🙂 I never got to see a Nascom 3. Any chance of some photographs before you send it?

  4. 6 Lars Jonsson 24/02/2018 at 4:09 pm

    Good info here. I found this site looking for “Animation Graphics Board”, I just got my AGB working in my Nascom 2. I don’t think it has run since 1987 or so.

  5. 7 PAUL F BEARD 02/04/2018 at 3:19 am

    I’m seriously thinking about fab’ing a NASCOM1 PCB. I built one in the late ’70s and it’s one of my fondest memories (I must be a looser). Other than the Apple I replica, there’s no old-school computer kits these days.

    Do you think others may be interested in a NASCOM 1 PCB and/or kit?


  6. 8 Tor 28/05/2018 at 9:36 am

    Bought a kit in 1978.. one of those with pre-soldered IC sockets. But I never got around to assemble it, for two reasons: There was no way I could afford to buy or build the power supply, something I didn’t realise when I got in on a group buy of the Nascom 1 (at tech. school). And I didn’t have anything I could use for a display – I have the impression that in the UK it was quite common to use the family TV for such things, that would not be acceptable in my country.
    However, I have finally acquired a +5V -5V +12V -12V power supply.. and setting up to assemble my Nascom 1. Still have to ponder on the display part, but now I think I can figure something out.

    • 9 Mick 28/05/2018 at 10:08 am

      Hi Tor,
      If you can find something that will accept a combined video input you should be ok as that is available on the Nascom 1. The original modulator circuit was very rarely used – most people opted for one of the “tin can” modulators that were much better. Those were supplied with the later kits too. A lot of us either found little computer monitors to use or bought 12 inch mono TVs. Unfortunately there aren’t a lot of either of those left!
      Good luck with your build!

  7. 10 Bob Webber 05/09/2018 at 12:51 am

    When I lived in England I had a Nascom 2 in the early 1980s It was still running n 1989. Also had a Gemini that I gave to my parents to use. I designed and built a Analog to Digital Converter (ADC) board for my Nascom. It had 9 channels of ADC using an 8 bit ADC Ferranti chip. 8 Channels were multiplexed to one ADC chip. The 9th channel went direct to a second ADC chip. This was to do near simultaneous sampling. The Board also had a Zilog PIO, SIO and Realtime clock chip with Battery Backup. I used this board to record my own ECG which was printed out on a dot matirx printer Epson MX80. I am a retired BioMedical Engineer, currently living in Maryland, USA. I can send a photo of this Board. I still have it. The Nascom 2 has long so gone, though I still have the DRAM memory chips for it. I had memory board and modified it to take 64K. Wrote that up or one of the Nascom magazines. I remember the names of David Hunt, Dave Greenhalugh (guessing at spelling of name)

    • 11 Mick 05/09/2018 at 1:24 pm

      Hi Bob 🙂
      Thanks for contacting me. That’s an interesting board, I’d love a pic if you could send one. Pity about your Nascom 2, but that’s how it goes. If your write-up is in one of the magazines that I have I can send you a scan of it. 🙂
      The bloke you are thinking of might have been Paul Greenhalgh.

  8. 12 Mathias Ohlerich 19/03/2020 at 5:07 pm

    I am interested in the Henelec Disk System leaflet. I could send five pages about the Henelec FDC.

    • 13 Mick 03/05/2020 at 6:55 pm

      Hi Mathias 🙂
      I’ve fixed my web page so you can read the leaflet that I have now. 🙂 Yes please – if you can contribute anything I’d be grateful.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

Nascom Pages