While resourceful owners could accomplish a lot with the 1K or 2K of RAM built in to their computers, more serious uses required more RAM. Sinclair and Timex offered 16K RAM units for the ZX80, ZX81 and TS 1000 computers. For many, that was enough.
A huge number of expansion RAM packs were produced for the Sinclair computers. Some extended beyond the default 16K, others claimed to address the “RAM pack wobble” problem and others made RAM available in special locations or configurations or had other special features.
Plans to expand 1K model to 16K or ZX81 with 16K to 32K for under $30. Fits inside ZX81.
ZX81 TS 1000
ZX80 TS 1000
TS 1000
TS 1000
TS 1000
TS 1000
TS 1000
TS 1000
Highly crash resistant RAM pack that can be mounted inside the computer under the keyboard or plugged into the rear connector. Requires no extra power supply; comes with a special high pressure edge connector.
TS 1000
Injection molded plastic case; overcomes wobble and disconnection problems characteristic of other units; optional extra is a keyboard sounder giving audible feedback when a key is pressed.
TS 1000
Upgrade to disk interface. Can be configured as RAM disk or port-mapped in 64K banks shadowing the cartridge bank.
TS 2068
Plans to expand memory up to 24K, using 2K RAM chips, placed anywhere from 8192 to 32768.
TS 1000
Plugs into the TS2068 cartridge slot. On board battery keeps it alive even when you turn the computer off. Switch selectable for use in the DOCK or EXROM banks with no mods to the computer. Write protect switch lets you use memory like an EPROM. Run your own plug-in BASIC programs. Detailed instructions include utilities
TS 2068
32k RAM inside the 2068, in the upper half of the DOCK and EXROM bank. RAM is active in the DOCK and/or EXROM bank, allowing user to save files that reside in the DOCK bank. Can also load files directly into this RAM from tape. Switch to disable the RAM in the DOCK bank so
TS 2068
Allows ZX81 to run 48K Basic programs including up to 16K of assembly code. ZX81 sits on custom built case containing the Memotech.
ZX81 TS 1000
Announced before 2068 launched. Manufacturer assumed 2068 would be identical to Spectrum.
TS 2000 TS 2068
ZX80 TS 1000
64K DRAM board for the TS1000, TS1500 or ZX81. Special features of this memory include: 8-12K on/off switch 12-16K on/off switch two banks of 8K ram available mapped 8-16K (Bank A/B switch) and 48-64K on/off switch
TS 1000
ZX80 ZX81 TS 1000
TS 1000
TS 1000
TS 1000
TS 1000
TS 1000
64K RAM upgrades which mount inside the TS 1000 or ZX81. Installs in a minute with no soldering, and easy to follow instructions. Disable the 10-12K, 8-12K, or 8-16K areas of memory with a switch. Models specific to the ZX81 and TS 1000.
ZX81 TS 1000
TS 1000
Documentation packet that covers memory pack troubleshooting. Includes plans for constructing your own memory pack, EPROM reader and extending the memory of the 16K RAM pack up to 64K.
TS 1000
16K RAM pack using CMOS 6116 static RAM chips for permanent data retention. Data can be stored almost indefinitely and loaded almost instantly with virtually zero chance of error. A long life (10 years) lithium battery supplies power in standby mode. In the active mode, power is taken from the ZX81. Used on its own,
TS 1000
Fits inside the ZX80/ZX81 and remaps internal RAM to 8-9K or 9-10K. For use with external RAM pack.
ZX80 ZX81
Non-volatile memory designed by Wilf Rigter. 32K RAM with Rigter Operating System (ROS). File-handling system in less than 600 bytes. Includes: DIRECTORY: displays all programs stored in memory by name and length in bytes. 44 entries per directory. SAVE: transfers BASIC programs, variables, and machine code to storage. Works in conjunction with the NAME/RENAME features.
TS 1000
TS 1000
Budget model 16K RAM supplied without case, gold-plated contacts. Designed to prevent wobble.
TS 1000
Memory expansion that fits inside the Fuller keyboard and requires the Fuller motherboard.
TS 1000
Memory expansion that fits inside the Fuller keyboard and requires the Fuller motherboard.
TS 1000
Up to 8K RAM or EPROM; works with 16K RAM packs. Store your own system utilities or build a library of machine language routines. Can be used with any ROM or RAM.
TS 1000
32K RAM operates in tandem with a 16K to provide up to 48K RAM. Compatible with the Data-Assette ZX99. LED power indicator.
TS 1000
Expands the 2068 with up to 256K of nonvolatile RAM. Includes LKDOS Extended BASIC cartridge and memory board that attaches to expansion port. LKDOS uses standard BASIC commands (LOAD, CAT, SAVE, etc) to operate the RAM disk. Uses 32K (62256) CMOS RAM chips backed up with a battery; comes with 64K. Compatible with Spectrum, OS-64
TS 2068
Low power, no extra power supply required. Area from 8-16K can be switched out in 2K increments to accommodate memory-mapped peripherals, EPROMs, etc.
TS 1000
Contains one or two 2K (6116) CMOS RAM chips. Memory is addressed into the ROM area from 8K-16K in the ZX-81 memory map. The address at which each chip appears can be adjusted to any 2K section within that area. Lithium battery in the unit provides a back-up power while the computer is switched off.
TS 1000
16K RAM unit expansion capabilities through its piggy back connection and is fully compatible with Timex or Memotech 16Ks to give 32K RAM.
TS 1000
The 32K Memopak could be combined with a 16K RAM for 48K RAM. It was initially incompatible with the 2040 printer.
TS 1000
TS 1000
16K or 32K and two 8-bit LS TTL input ports and two 8-bit latching output ports.
TS 1000
Memory mapping device to expand address space from 64K bytes to 1 megabyte. Organized into vertical 64K pages. Up to 16 pages can be supported. All memory can be dynamically defined from within a program, allowing (for example) a program in one segment to manipulate the contents of various data segments. A module in the
TS 1000
512K RAM expansion for the Sinclair QL featuring no wait-state memory and full through port.
QL
Low cost memory expandable from 2K to 8K. Located in an address space not used by BASIC. Ideal for data or machine coded routine shared by second program. A module in the BASICare Modular Expansion System.
TS 1000
16K memory module. On-board address decoding permits simultaneous use of many RAM 16 modules in conjunction with Minimap. A module in the BASICare Modular Expansion System.
TS 1000
Arranged in 4 blocks of 16K; all can be used under MINIMAP control. On board address decoding allows simultaneous use of many modules with MINIMAP. A module in the BASICare Modular Expansion System.
TS 1000
Announced before 2068 launched. Manufacturer assumed 2068 would be identical to Spectrum.
TS 2000 TS 2068
Integrated expansion system. Analog, digital I/O ports and 16K RAM expansion on one card.
TS 1000
Improved version of Hunter board. Comes with battery-backup to make memory non-volatile. Developed with Larken Electronics to support Silicon Mountain’s WRX-16-based high-resolution software. Mapped in the 8K from 8-16K block. Can be re-mapped to 16-24K or 24-32K. Three SCRAM boards can provide 24K RAM for the ZX81 or 40K for the TS 1500. BOARD ENABLE
TS 1000
SCRAM board with two 8K static RAM chips, mapped to the normal 16-32K RAM region. Top 8K can be switched out in 2K blocks, allowing you to keep machine-code above RAMTOP.
TS 1000
Efficient design, uses less power. Gold-plated, heavy-duty connector prevents glitches.
TS 1000
Fits inside computer; plugs in, no soldering; up to 16K in increments of 2K. Uses 6116 static RAM.
TS 1000
Timex’s version of the Sinclair ZX81 16K RAM pack for the Timex/Sinclair 1000. This, and the Sinclair unit, were famous for “wobble,” a condition that resulted in resetting the computer and loss of memory contents. Users overcame this problem with a variety of solutions, including Velcro between the computer and RAM pack, oversized rubber bands,
TS 1000
Prototype RAM expansion module. Internal circuit board marked “TS-1032 REV A.” Has 16 AM9016EPC 16K x 1 bit RAM chips, total of 32K RAM. Date codes on all chips are 1982, the latest is the 50th week of 1982. Only one confirmed to exist. From Eric Johnson’s collection.
“Ultimate memory” RAM pack. Battery backup, reset switch, PROM/ROM socket.
TS 1000
64K RAM pack with additional features. 8-16K area selectable in 2K increments. EPROM socket for 2K/4K. Battery backup (6 AA batteries) powers RAM pack and computer for up to 30 minutes. ROM-RAM transfer: copy Timex ROM into the 0-8K area of RAM, flip a switch and operate out of RAM. Switch that only resets 16-32K
TS 1000
Contoured case fits snugly against the rear of the computer. LED power indicator. Expandable to 32K with plug-in module that fits inside the existing case.
TS 1000