1292 Compatibles Programmable Video System
Database Computer
voltmace_db

The Voltmace Database Games-Computer

VoltMace Database Games-Computer is a cartridge based early 1292 system. The machine software compatible with the Audiosonic 1292 Advanced Programmable Video System and all the other 1292 style console systems. Unfortunately different manufacturers of the VC4000 produced slightly different versions of the cartridges, and even though the software is compatible, sometimes the cartridges are not due to the different form-factor.

CPU View - Signetics/Philips 2650

The Signetics 2650 was a 8-bit microprocessor produced by Signetics in 1975. It came in a 40-pin DIP package, had 15 address lines and could run at 1.2MHz.

The CPU was designed in 1972 by a team led by John Kessler of IBM, to compete with the minicomputers of that time. The CPU was produced using the NMOS process which used less power and produced less head than PMOS CPU designs. The base for the design was the 1130, which was a 16-bit minicomputer released in 1965.

The Signetics 2650 was one of the most advance CPUs of 1972. It easily outperformed the Intel 4004 and 8008. Due to production delays the CPU was not formally released until 1975, by which time other CPUs had been introduced that were designed from the ground up, rather than based on a mini-computer design. In 1975 Signetics was bought by the Dutch electronics company Philips.

The Signetics/Philips 2650 has four main general purpsoe registers (REG0..REG3) and three Alternate general purpose registers (REG1'..REG3'). It has one instruction addresss register, and a return address stack of 8 15-bit words. The Alternate registers could be switched between with a single instruction that controlled a bit in the status register called PSW. This allowed rapid switching of values during subroutines, interrupt handling and OS level task switching.

The Signetics 2636 Video Controller

The 2636 Programmable Video Interface has 108 registers that control its audio and video output. Four other register provide the processor with information about video object collisions and provide input for the analog joystick data. Another 37 registers function as general purpose memory locations. The PVI also generates chip select signals for various functions on the game cartridge. It can send an interrupt request signal to the CPU.

The 2636 PVI is capable of generating a single square wave frequency which is then fed to other circuits that generate audio effects such as explosions, white noise or beeps.

Magnified image of the 2650A die

Advertisement for the 2650 CPU

Technical Details
Released 1978 Country United States Brand Voltmace Type 1292 Compatibles Programmable Video System Name Database Computer CPU Class CUSTOM CPU Signetics 2650A @0.887MHz Memory RAM: 37 bytes
RAM max: n/a
ROM: none
VRAM: none
Sound Chip none Sound Single Square wave frequency. Display Chip Signetics 2636 Video Controller Display 218x200 in 8 colors Best Color 8 colors Graphics unknown Sprites 4 single color sprites Storage ROM cartridge
External Links 🌐
Signetics 2650 CPU
Wikipedia page for the Signetics/Philips 2650 CPU