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The Memotech MTX Series

The Memotech Library

Technical Data for the MTX Series

Component Data Sheets

 

There are many sources for component datasheets on the internet, including the manufacturers, component suppliers and colleges/universities, so most datasheets are easy enough to find with a quick "Google". However, the components used in the Memotech range are now very old and mostly obsolete, so datasheets are sometimes very hard, if not impossible, to find. I have spent a lot of time trying to find datasheets for these obscure components, sometimes successfully and sometimes not. I have posted them here in case they are useful to others, if you have copies of any of the ones highlighted that I don't have, I would appreciate a copy or link to them. This page is a work in progress, I do have a few other datasheets that I will be adding shortly.

Note: Most of the "alternative" components listed below are based on datasheets that I found when looking for those of the original Memotech suppliers. On comparing these datasheets with the originals, I believe them to be compatible, apart from a couple of exceptions, as indicated below, I have not actually tried them - if you can't find the original components, you might like to try the suggested alternatives - at your own risk of course :-) Components indicated like this, are not likely to be compatible with the MTX.

The more significant components such as floppy disk controller and CRT controller ICs are discussed on various pages on the site. Other components are not specifically referenced, but this page will eventually be a placeholder for all ICs and major components used in the MTX series of computers.

My interest in this data relates to its use in the Memotech MTX series of computers and related hardware, this means that for me, the most useful data sheets are from that period and are almost certainly not the most current, if you are looking for up to date information, the datasheets here will likely have been superseded.

Most of this information comes from long defunct publications, I don't imagine that the copyright holders, are vaguely interested in these pages, but if anyone has issues with me making this information available, let me know and I will remove the offending item(s).

A word about quality : these datasheets come from a range of sources and while all are easily readable, some have rather better quality than others. If you have better copies than I have posted here, if you send me a copy, I will update the site.

 

MTX Computer Board Dynamic RAM (Original : OKI 3764-20)

 

Extract from the OKI Data Book showing 3764 compatibility with some other DRAMs, click image to see complete table

 

 

Click to open PDF

Generic

Designation

Manufacturer

Manufacturer's

Designation

Comments

4164 OKI (MS)M3764-20RS

RAM (MTX512/RS128)

4164 Hitachi HM4864A-3

OKI Cross Reference for 3764

4164 Texas Instruments    TMS4164A-20

OKI Cross Reference for 3764

4164 Motorola MCM6665A-20

OKI Cross Reference for 3764

4164 NEC uPD4164A-2

OKI Cross Reference for 3764

4164 Mitsubishi M5K4164A-20

OKI Cross Reference for 3764

4164 Fujitsu MB8264A-20

OKI Cross Reference for 3764

4164 Motorola Semiconductors MCM4164CP

(A possible alternative)

4164 Samsung KM4164B

(A possible alternative)

   

 

 

MTX512S2 Computer Board Dynamic RAM (Original : Various, including . . . ) read this

Click to open PDF

Generic

Designation

Manufacturer

Manufacturer's

Designation

Comments

41256 Hitachi HM51256-15 In my Video Wall MTX512S2

41256

  Timing data

 only

NEC    uPD41256C-15 In my non-Video Wall MTX512S2

41256 NEC uPD41256C-10 (An alternative to the NEC component)

41256 Texas Instruments TMS41256-10 In my Video Wall Reflex

41256 OKI MSM41256A (Not seen used, should be compatible)

 

 

MTX Computer Board Video RAM (Original : ITT 4116 3N)

Click to open PDF

Generic

Designation

Manufacturer

Manufacturer's

Designation

Comments

4116 ITT 4116 3N

Video RAM (All models)

4116 AMD AM9016

(An alternative to the ITT component)

4116 Mostek MK4116P

(An alternative to the ITT component)

4116 Motorola MCM4116A

(An alternative to the ITT component)

4116 Texas Instruments TMS4116

(An alternative to the ITT component)

 

 

ROMs

Click to open PDF

Generic

Designation

Manufacturer

Manufacturer's

Designation

Comments

3864 OKI M3864-06

8k (64k x 1) Mask ROM

2764 Mitsubishi Electric M5L2764K-2

(An EPROM alternative to the ROM)

2764 ST Microelectronics M2764A

(An EPROM alternative to the ROM)

2564 Texas Instruments TMS2564

(Unusual ROM seen at Memofest)

38128 OKI M38128

16k (128k x 1) Mask ROM

27128 ST Microelectronics M27128

(An EPROM alternative to the ROM)

27128 NEC uPD27128

(An EPROM alternative to the ROM)

 

 

74 Series Logic (Originals : Predominantly Texas Instruments)     74 Series Nomenclature

Click to open PDF

Generic

Designation

Manufacturer

Manufacturer's

Designation

Comments

74LS00 Texas Instruments SN74LS00 Quad 2 Input NAND Gates

74LS04 Texas Instruments SN74LS04

Hex Inverters

74LS08 Texas Instruments SN74LS08

Quad 2 Input AND Gates

74LS14 Texas Instruments SN74LS14

Hex Schmitt Trigger Inverters

7416 Texas Instruments SN7416

Hex Inverter Buffers / Drivers

74LS27 Texas Instruments SN74LS27

Tri 3 Input NOR Gates

74LS74 Texas Instruments SN74LS74A

Dual flip-flops with Clear

74LS138 Texas Instruments SN74LS138

3 Line to 8 Line Decoder/Mux

74LS157 Texas Instruments SN74LS157

Quad 2 Line to 1 Line Selectors/Muxs

74LS157 Motorola Semiconductors SN74LS157

(An alternative to the TI component)

74LS163 Texas Instruments SN74LS163A

4-bit counter

74LS163 Motorola Semiconductors SN74LS163A

(An alternative to the TI component)

74LS166 Texas Instruments SN74LS166A

8-bit shift register

74LS175 Texas Instruments SN74LS175 Quad "D" Type flip-flops

74LS175 Motorola Semiconductors SN74LS175 (An alternative to the TI component)

74LS193 Texas Instruments SN74LS193 4-bit counter  with Clear

74LS244 Texas Instruments SN74LS244 Octal Buffers / Line Drivers

74LS245 Texas Instruments SN74LS245 Octal Bus Transceivers

74LS273 Texas Instruments SN74LS273

Octal "D" Type flip-flops with Clear

74LS273 Motorola Semiconductors SN74LS273

(An alternative to the TI component)

74LS367 Texas Instruments SN74LS367AN

Hex Bus Drivers

74LS367 Fairchild Semiconductor DM74LS367A

(An alternative to the TI component)

74LS373 Texas Instruments SN74LS373

Octal Transparent Latches

74LS374 Texas Instruments SN74LS374

Octal Edge Triggered flip-flops

74LS374 Fairchild Semiconductor DM74LS74A

(An alternative to the TI component)

 

Application Specific

6116 Hitachi HM6116P-4

Speculator 16k Static RAM (2k x 8)

6116 IDT IDT6116

(An alternative 2k SRAM)

7805 Texas Instruments LM7805C MTX Voltage Regulator : 5VDC
7812 Texas Instruments LM7812C MTX Voltage Regulator : 12VDC

FD179x-02 Western Digital FD179x-02

FDX/SDX05 : Floppy Disk Controller

LM1889 National Semiconductor LM1889

Video board : TV/Video Modulator

MC6845 Motorola Semiconductors MC6845

80 column board : CRT Controller

(Info on the Amstrad CPC Wiki )

  6845 Pravetz CM607P

Bulgarian Clone of MC6845

6845 Thomson Semiconductors EF6845P

Thompson Clone of MC6845

PAL14L4

Monolithic Memories

(AMD / Lattice Semi.)

PAL14L4

Various : Custom Logic Functions

GAL16V8 Lattice Semiconductor GAL16V8

Can be coded to replace a PAL14L4

SN76489AN Texas Instruments SN76489AN MTX Complex Sound Generator

TIP2955 Texas Instruments TIP2955 MTX Power Transistor : 5VDC

TIP2955 ST Microelectroncs TIP2955 (An alternative to the TI component)

TMS9918A / 29A Texas Instruments TMS9918A

MTX Video Display Processor

Z80 Zilog CPU Specification Z80

MTX CPU

Z80CTC + Zilog Counter/Timer Chip Z80CTC MTX Counter / Timer

Z80DART + Zilog Dual Async Rx/Tx Z80DART RS232 Board : Communications
         
         
         

   + Datasheet courtesy of Paul Daniels

 

MTX512S2 - 256 k RAM

The MTX512S2 and other 256k MTX computer boards, do not use RAM from a single supplier like the 64k and 32k boards do. I know of at least three different suppliers, NEC, Hitachi and Texas Instruments. Whilst the specs that I have been able to find for the various DRAMs used would indicate that they are compatible, in practice, there seems to be some inconsistencies in the performance of one type of RAM with another in certain machines. It is not known why this should occur, but you **may** have a problem if replacing one manufacturer's RAM with another's.

I mention this because whilst I have been successful in replacing the NEC D41256C-15 RAM in my non-Video Wall MTX512S2 with NEC D41256C-10 RAM, Andy has had problems using the same RAM to replace the (unknown) RAM in his MTX512S2.

 

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Page last modified 27/04/2015