General Information
The RCA Studio IV is a console that was never released by RCA. Information here is based on the Studio IV Interpreter and prototype schematics for the video card.
The Studio IV Interpreter by Joe Weisbecker was extracted by Andy Modla from tape S.572.21B from The Sarnoff Collection, The College of New Jersey.
The prototype schematics part A and B were made available from the Hagley Museum and Library: Sarnoff/RCA Collection - Joseph A. Weisbecker's archived manuscripts and materials - M&A 875, Folder 19
The Studio IV is very similar to the Studio III and MPT-02 consoles. Differences include a more extensive pseudo code interpreter in a 2 KB ROM and an improved video chip.
The disassembled Studio IV Interpreter including the complete pseudo code instruction set can be found here, pseudo code syntax is also shown on ST4 Syntax
Tiny BASIC
Tiny BASIC as released on the VIP VP700 board was also ported by RCA to the Studio IV. Initially only half (second 2K) of the original code was discovered, at the time I was able to port the VIP routines for the missing half to the Studio IV. So the code provided for these versions is not fully original.
Four '2020' versions are provided in the Emma 02 archive:
- PAL for use with 32K RAM
- NTSC for use with 32K RAM
- PAL for use with 4K RAM
- NTSC for use with 4K RAM
My assumption is that 4K was as developed by RCA as Studio IV colour memory is located at address hex 2800 limiting the RAM options. For the 32K RAM version I moved the colour memory to hex 1000.
Recently the source code for the second half of Tiny BASIC was found at the Hagley Museum and Library. Which means we now also have the original code which was only written for an NTSC version and max 4K RAM. This version is included in the Emma 02 archive as 'am4kbas 1978.bin'.
Emma 02 includes an assembler and dissassembler for both pseudo code syntaxes which are more or less the same. See here: AM4KBAS for the Studio IV syntax and here: AMVBAS for the VIP syntax.
Super-chip
The Super-chip interpreter was designed by me. I started this during the covid-19 pandemic in 2020. Initially for a modified VIP (same HW mod as for the chip10 interpreter) but now also ported to the Studio IV.
The Studio IV port was actually fairly easy. However, as Super-Chip is supposed to run from RAM, it is not compatible with a real Studio IV if we would ever find one. Instead it runs from RAM but from the cartridge ROM memory location.
For more details and explanations for start-up settings see Super-chip Syntax.
Technical specifications
Clock: 3.58 MHz
Memory:
256 Bytes RAM, possibly more!
1 KB Video RAM
1 K 4 bit Colour RAM
2 KB ROM
Video: 'Studio IV' chip, probably an improved 'CDP1864'
Sound: Same as the CDP1864
Keyboard
Screen shot
Studio IV running the build in demo / screen saver
Links
Other information about the RCA Studio IV:
Main Features Studio IV Emulator
- Adjustable speed, boosting the speed of the Studio IV beyond 3.58 MHz!
- Video support for the Studio IV video chip with zoom and full screen option by pressing F3
- Sound support as for CDP1864
- Cartridge support (.st2 file format)
- Video screen dump to a file (BMP, JPEG, PNG or PCX image)