Spectravideo X'press (SVI-738)

It's an MSX-compatible (MSX version 1, but with some extensions from v.2) computer, popular in Polish schools. There wasn't much Polish software for it, as it was probably only MSX known in Poland.
Floppy disk drive and BASIC ASCII capabilities made this computer good in data processing, but floppy disk drive was noisy (despite all rubber pads and springs) and formatted only one side of 3.5-inch disk. Finally, it was mostly used to teach BASIC programming.
It was called X'press, as it was relatively small and was offered with bag for easy transporting.
In fact, Spectravideo X'Press is more MSX 2 than 1. It seems that engineers planned to do something better, but costs didn't let them put it to production. First mainboards had ready pads for battery-backed RTC, one of MSX 2 standard requirements.
In fact, to convert it to MSX2 (except this clock), you have only to add more VRAM, change ROMs, get the missing ROM address line and ground one line in RS232 ROM driving circuit.
More, putting AC transformer in external case, but leaving switching regulator with hot Gretz bridge in the computer seems to be quick-and-dirty solution to interference problems. 


Manufacturer Spectravideo

Origin Hong Kong
Year of unit 1987
Year of introduction 1986
End of production ?1988?
CPU Z80
Speed 3.5MHz
RAM 64K
ROM 56K (32K BASIC, 8K serial, 16K FDC)
Colors: 256
Sound: 3-channel AY-3-8910
OS: MSX BASIC,
MSX DOS
CP/M 2.2
Display modes: Text: 40x24, 32x24, 80x24
Graphic: 256x192, 64x48.
 
 

 

Media: Tape
ROM Cartridge
Built-in floppy disk drive
 

Power supply:

A female DC Jack at the computer:


1, 2 - 16V AC at 2A.

DC can be used in any polarity, but avoid it, as diodes may get hot after extensive use.

I/O: 2x Joystick
Tape
Serial port (RS232)
External FDD,
Printer (merely Centronics compatible)
Composite video
Audio
RF out
 
 
 
 
 
 
Possible upgrades: To +/- MSX2 standard
   
Software accessibility: Quite easy (dedicated MSX sites) Dedicated accessories in collection:

My unit comes from school, so it had all damages it could get in school. FDD had to be replaced, as head was damaged by sticking pencil in there. I don't know if cartridge slot works, as I spent over hour with pliers making pins straight in their places. Cartridge door's hinge was broken on casing's side, fortunately it's easy to fix by glueing piece of round plastic inside (in my case plastic piece of wall screw plug cut to fit and act as hinge).

My unit, sold by Składnica Harcerska, is converted to support diacritized Polish characters: It has modified keys to show these characters on keys and modified ROM, to get them on screen with CODE/GRAPH keys.


Contents: Starting Recording media Pinouts Links

Starting:

It boots to MSX BASIC, where you can use commands native to MSX BASIC:
MOTOR ON or MOTOR OFF - turns cassette motor on and off, usable when motor driving connector is connected to cassette player.
CLOAD - loads MSX BASIC file from cassette. You use: CLOAD "PROGRAMNAME" or to load the first one - just CLOAD.
To verify program written with CSAVE "PROG1", you have to type CLOAD?"PROG1".
LOAD"CAS:PROGNAME" - or LOAD"CAS:" - loads ASCII file, may be also BASIC program saved with SAVE"CAS:PROGNAME".
BLOAD"CAS:PROGNAME" or BLOAD"CAS:" - loads a machine code program (binary) from cassette.
LOAD and BLOAD may have additional ,R parameter at the end (for example BLOAD"CAS:",R). With this the program will be started immediately after loading.

To load from disk, check first is diskette bootable by trying to boot computer from it.
If not, use FILES command to list contents in BASIC.
Now, you can:
RUN"[1:]PROGNAME" - loads and runs program from disk. Some MSX BASIC versions have not 1: but A: drive letters.
LOAD"[1:]PROGNAME" - Loads BASIC file.
BLOAD"[1:]PROGNAME" - Loads binary file.

If you put a CP/M or MSX-DOS disk to the computer and start it, it'll bot into CP/M or MSX-DOS. CP/M commands are similar to DOS.
 

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Recording media

Recording disks from DSK requires PC with floppy drive. Floppies usually must be formatted in Spectravideo before making, so to format it, use
CALL FORMAT
command from BASIC on Your Spectravideo.

DSK files may be recorded with Disk Manager, but not all of them. Some requires DCOPY, making of DSK can be done with DCOPY too, but to make it working properly you have to run in in PURE DOS, NOT in Windows.

IMG files are usually CP/M files, and can be recorded using COPYQM (available in my fileland with SVI-738 system disks) with the following command:
COPYQM A: PLAYBACK=IMAGE.IMG

Tapes are usually stored as CAS files, they may be just played from sound card. Use CasTools to process CAS to WAV and in reverse way.

 

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Pinouts:

External floppy disk drive:

1 - +12V
2 - +5V
3 - +5V
4 - /INDEX
5 - /DSEL1
6 - DIRECTION
7 - /STEP
8 - WRITE DATA
9 - /WRITE GATE
10 - /TRACK0
11 - /WRITE PROT.
12 - READ DATA
13 - /SIDE SEL
14 - +12V
15 - +12V
16 - +5V
17 - /DSEL0
18 - MOTOR ON
19 - READY
20 - GND
21 - GND
22 - GND
23 - GND
24 - GND
25 - GND

You can use normal PC drive, but if you plan to use PC FDD as internal one, be sure to select it as drive 0 - DS0, not DS1 as it was in PC. Older drives have jumpers to set it. Newer - solder pads. Successfully used Alps drive only by modifying its solder pads.

 

Tape connector:

1-3 - GND
4 - DATA OUT
5 - DATA IN
6 - RELAY
7 - RELAY
8 - GND

Computer controls relay - to start/stop tape, pins 6 and 7 are connected together when tape must be running.

Printer connector - 14-pin female Centronics-type connector:

1 - /STB
2 - PD0
3 - PD1
4 - PD2
5 - PD3
6 - PD4
7 - PD5
8 - PD6
9 - PD7
10 - NC
11 - BUSY
12 - NC
13 - NC
14 - GND

RS232 connector (not sure about it!):

1 - GND
2 - TxD
3 - RxD
4 - RtS
5 - CtS
6 - DSR
7 - GND
8 - CD
9 - DTR

In many cases you can use this port to exchange programs - just use COM0 device, for example:
LOAD"COM0:"

 

 

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Links:

http://www.faq.msxnet.org/ - MSX FAQ - Everything you want to know.
http://msx.hansotten.com/ - Many useful docs, for example converting SVI-738 to MSX2.
http://www.bluemsx.com/ - Emulator and games database, some with download.
http://web.archive.org/web/20040610094214/http://svi.s31.pl/ - in English, site ran by Polish collector, many interesting facts about SVI.
http://www.msxarchive.nl/  - Lots of downloadable software
http://msx.fi/nyyrikki/pc.html  - Some software.
http://fms.komkon.org/MSX/  - Some nice resources from MSX fans Usenet.
http://www.spectravideo.org/manuals.html - Manuals, screenshots and projects for SVI. Use subpage to enter.
http://www.samdal.com/spectravideo.htm - Resources, schematic of SVI-738.
 

 

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