hallath: CGL M5

hallath is an M5, a small computer just slightly larger and heavier than a Spectrum. It has a nasty rubber keyboard and Spectrum-style one-key-one-BASIC-keyword shortcuts (although unlike Spectrum BASIC, the builtin BASIC allows you to type the keywords in full if you prefer). The keyboard's biggest failing is the fact that the 'spacebar' is in fact a space key just under the return key.

hallath came with a BASIC cartridge and a game cartridge (Guttang Guttong, a sort of arcade puzzle game involving a train on a sliding blocks puzzle). The cartridges are essentially just ROMs that plug into an edge connector. It uses a separate power supply brick to provide regulated +5, +12 and -12V supplies.


hallath used to be owned by a friend. Like tegath and serith it is essentially a home computer that got left behind by the remorseless advance of technology.


Outside View

view of the case
Note the cartridge slot at the top right. There used to be a flap that covered the grey top section (not a lot of use since it was always up when a cartridge was inserted, and you need a cartridge to do anything...) but it has been lost at some time in the past...

Interior View

view of PCB

The video modulator is the box at top left. The RAM is bottom right, and there is a TMS9929 to the left of that. On the right hand side is an EPROM, a blank space and two ROMs. To the left of that is a custom IC, the Z80 CPU and a Z80 CTC chip.
NB: to take this shot I had to remove a metal shielding plate that had been soldered into place. I do dislike designs that aren't intended to be easily repaired...

View of Space Key

view of space key
This is the really nasty space key...
This page written by Peter Maydell (pmaydell@chiark.greenend.org.uk).