Home > Previous Page >  Jupiter Ace RAM packs
Archive Search  

Ram packs are external memory modules that expanded the Ace's memory. Jupiter Cantab manufactured two size 16k and 48K giving the Ace a memory capacity of 19k or 51k respectively. Another manufacture of Ace RAMpacks was Stonechip Electronics with there Pace 16K expandable to 32k RAM pack. In the 1980's such RAM packs were expensive and users resorted to make there own RAM packs or use a ZX81 RAM pack.

Below are the RAM pack images of the Jupiter Cantab 16K, and some home builds.

 Jupiter Cantab 16K RAMpack.

The RAM pack in its Poly packaging. Below, an image of how the case fits together with the plastic location tabs and slots in the top of the case. The case is tight neat fit and well made.

Component side of the PCB, using 4116 RAM chips.

Solder Side.

Any one got a schematic for this RAM pack? The Instruction are here as a pdf.
[Back to top]
Jupiter Cantab 48K RAM pack.

Boldfield 48K RAM pack.

Boldfield computing sold a 48K RAM pack manufactured by Cambridge Technology Group (CTG) which was a modified 64K ZX81 RAM pack. The ACE version needed an adaptor board with a ZX81 edge connector lay out such as motherboard card sold by Boldfield.






Can anyone help with a schematic for this RAM pack or instructions?
[Back to top]
SH 16K RAM pack.

It also looks like this home build has a keyboard connector built into it as well.

[Back to top]
IBM 16K RAM pack.

This memory board was made from part of an old IBM Memory Typewriter (hence a lot of removed parts and some of the board cut off) it is basically just 16K of Low Power Static RAM (8 Chips of 2K each) with addressing wired to suit the Ace (mapped as per a ZX81 16K RAM Pack). Some circuitry which was part of the original board will provide battery back up. It was built specifically for the Ace. This is an in a USA Jupiter ACE hardware collector and is in working condition.

[Back to top]
Pace 16K

Manufactured by Stonechip Electronics this RAM pack can be expanded to 32K with a daughter board. The RAM pack also has a red LED to show that the pack in operation.

Has anyone got a schematic for this?
[Back to top]
Pace 16K daughter board.

Manufactured by Stonechip Electronics this add on module when plugged into the Pace16K RAM pack increases the RAM packs capacity to 32K.

Has anyone got a schematic for this?
[Back to top]
Pace 32K (16K RAM pack + 16K daughter board.

[Back to top]
EB 96K RAM pack

For more details on this RAM pack see here

[Back to top]
Woodvine 4K RAM pack

Made by Will Woodvine back in June 1984! Ace users used many different methods to get extra memory. The technique used in this home build was to "piggy back" two 6116 2K x 8-bit chips. This technique was also used with the ZX81, but this is the first time we have seen it on the Jupiter Ace RAM pack. The logic for the RAM chips is controlled by a 74LS138 decoder. The RAM pack is well built into plastic box with holes drilled thought the front face for the solder contacts of the edge connector. Then the edge connector was glued in place, red LED is also present to show power is on. On the back plate of the box is a simple schematic of the RAM pack.

Front showing the LED top left.

Top of the veroboard showing the 6116's and the 74LS138 to the right.

6116's "piggy back" close up. Note that the top 6116 has it's pin 18 bent out and
the white wire soldered to it controls the logic

Solder side of the RAM pack.

Back Plate showing the schematic.
[Back to top]
Downsway 48K RAM pack

Made by Downsway Electronics (UK)Ltd Epsom Surrey.

Gives a full 51K of RAM - light,snug-fitting unit with all the outstanding features of other Downsway memories - finished to match the new Jupiter Ace case Only £59.95 - from the advert in Your Computer, September 1983.

[Back to top]