YABUS.TF expands memory of Timex FDD 3000 to 4MB DRAM and 8kB EPROM (512kB with FlashD0). Two YAMOD modules can be connected.
Extension dedicated to Timex FDD 3000 with big main board (not those based on Timex FDD 3). This board has soldering points on the right hand side, marked as P9. Allows to connect hard disk and run operating systems as UZI, also run software for Z88 computer.
Beside you can see the inside of Timex FDD 3000with YABUS.TF plugged in. The slots on YABUS.TF are arranged so one YAMOD board is under and secoond is over a drive (this applies to 1" high drive, e.g. FDD 3.5" or HDD).
Before 2004 the former YABUS.TF has only 256kB DRAM and now got upgraded to 4MB.
- Booting the system from any drive, in which is the boot disk (not only the "DRIVE A").
- Extending TOS to allow floppy diskimages on hard disk.
- Using CPM22QED YTF with 59kB memory for programs (TPA).
- Access to harddisk via YAMOD.ATBUS or YAMOD.IDE8255 board.
- Booting the system from harddisk.
- Using the UZI (Unix Z80 Implementation).
- Using Timex FDD 3000 as TNC modem (Packet Radio).
- Dedicated for Timex FDD 3000 with big board (with two EFGJ square chips).
- The memory mapping idea is compatibile to Z88 (#D0..#D3 ports).
- There are 8kB ROM and 4MB RAM, internal memory is disabled and not used.
- Two unbuffered YABUS slots.
- EPROM with expanded startup code.
- Up to 2MB writeable Flash ROM (ROM-disk).
|section B||RAM00||..||RAM7F||reserved for ISA cards|
- RAM00..RAM7F are available in every section.
- RAM1F is dedicated for system purposes (used by ROM80).
- RAM80..RAMFF are available only in sections C and D.
- ROM80..ROMFF are available only in section A.
- On the right hand side there are soldering points marked as P9. In this place a female edge slot is mounted (the slot is like used in ZX81 interfaces).
- The YABUS.TF is plugged into the extra edge slot.
- On the board, one track must be cuted to disable internal DRAM. A transistor can be mounted in the cuted track, controlled by ROM disable signal to enable internal RAM when the YABUS.TF is removed.
- The YAMOD interfaces are connected to the YABUS slots.
- Some of YAMODs can requre extra holes in rear case wall.
Files for download
- timexset.jpg 39.4kB (2005-03-03 17:11)
- Timex FDD 3000 with 3.5" floppy disk drive, YABUS.TF, YAMOD.ATBUS, HDD and Timex Computer 2048, YABUS.ZX, YAMOD.AYLPT, TI-of-TTL.
- tffix.png 33.3kB (2004-11-10 00:05)
- Schematics of fix needed for Timex FDD 3000 board to disable internal 64kB RAM.
- yabustfview4.jpg 90.2kB (2004-07-17 00:57)
- YABUS.TF - the final version with 4MB RAM - top board view.
- yabustfview3.jpg 74.3kB (2004-07-12 13:38)
- YABUS.TF mounted into Timex FDD 3000 - inside view. Board with 256kB RAM, before upgrade to 4MB.
- yabustfview2.jpg 75.6kB (2004-07-12 13:38)
- YABUS.TF mounted into Timex FDD 3000 - outside view.
- yabustfview1.jpg 66.0kB (2004-07-12 13:38)
- YABUS.TF - top board view. Board with 256kB RAM, before upgrade to 4MB.
- 4mbybtf.zip 23.5kB (2004-06-13 16:02)
- 4MB RAM upgrade for YABUS.TF.005. Eagle data files.
Links to other pages
- YABUS - universal 8-bit magistral
- Description and documentation for YABUS slots and YAMOD modules.
- 4MB RAM extension for Timex FDD 3 with YABUS support.
- YAMOD.ATBUS 8bit IDE
- The fastest 8bit universal IDE multiplexer for YABUS. Includes RTC type DS 1287, DS 12887 or MC 146818.
- Dinamic Random Access Memory (DRAM). Memory with multiplexed address lines.
- Timex FDD emulation - YTF
- Timex FDD emulation based on Warajevo 2.51, includes YABUS.TF upgrade and IDE interfaces. Requires PC @ 100MHz.
- CPM22QED YTF
- CP/M 2.2 compatibile system for Timex FDD with YABUS.TF(3) upgrade. Supports YAMOD.IDE8255 and YAMOD.IDE8255.
- 128KB - 512KB PEROM - FlashD0
- 128KB or 512KB PEROM (or Flash EPROM) for Spectrum compatibile computers. Can support 4MB RAM upgrade and be base for ZXVGS installation.