vLA81 : ZX81 ULA replacement
The vLA81 is a modern plugin replacement for the ZX81 ULA.
These are new ULA replacements created and manufactured by Charlie Ingley. He sells these direct, but due to being located in New Zealand, postage and import costs to the EU/UK mean costs increase substantially. We are pleased to have worked with Charlie in order to be able to resell these at a reduced total cost for you compared with having to buy direct.
Apart from providing the functionality of both the earlier 2C158E/184 ULA (without back porch) and the 2C210E (with back porch), the vLA81 also has a few extras added.
- Fits within the same 40 pin DIL socket outline as the original ULA.
- Narrow IC pins for easy plugin ULA replacement. In most cases the existing socket will be OK (unless, of course, the existing ULA is soldered in).
- Provides the same functionality as the 2C210E Sinclair ULA.
- Video level selectable between standard video (suitable for direct connection to a 75 ohm monitor input) and high sync level (suitable for the modulator input or some video mod boards).
- Back porch on/off select.
- Internal 32K memory support (High or Low for the different hires schemes).
- Programmable user configuration gives access to:
- Inverse or normal video and choice of black or white border.
- 50/60 Hz video standard.
- Ability to map ram to the ROM space (write protect enable/disable – 32K internal ram required).
- Configuration port socket provided on PCB base for external config switch (optional extra).
- Tested with an extensive suite of ZX81 software.
- Ideal for preserving the original ZX81 ULA.
- Low power consumption.
For full details please see Charlie's site here: vdrivezx.com/vla81/
This product was added to our catalog on Wednesday 18 September, 2019.