The NLQ401 is a Near Letter Quality printer from Schneider, for use with German Schneider CPC computers. The SFT401 tractor feed add-on was sold separately. Both NLQ401 and SFT401 were advertised as official Schneider expansions on the back of the german CPC6128 users manual.
For (detailed) general information about Amstrad/Scheider printers, see:
- Amstrad/Schneider Printer Models
- Amstrad/Schneider Printer Technical Specifications
- Amstrad/Schneider Printer Control Codes
- Amstrad/Schneider Printer Support for 7bit Printer Ports
- Amstrad/Schneider Printer Character Sets
- Amstrad/Schneider Printer Buttons and DIP Switches
- Amstrad/Schneider Printer Resources (User and Service Manuals, Datasheets, ROM-images)
- The NLQ401 PCB can be optionally fitted with RS232 interface (25pin DSUB connector, and 75188/75189 voltage converters, this might also require a different firmware version).
- As seen on the photo, the board contains a uPD7811G processor, but its internal ROM is disabled via MODE0/MODE1 pins, so it does act more like a ROM-less uPD7810. According to the NLQ401 service manual either uPD7810 or uPD7811 can be used.
- The 16K EPROM is mapped to address 0000h..3FFFh. The MODE0/MODE1 pins are wired so that external memory uses only 14bit addresses (the upper 2bit of Port F are used as I/O signals, rather than as address bits)
- CPC Schneider International, March 1985, page 24 (german) (this review contains some misleading info; among others claiming that it can print in 11 different character heights, as well as claiming that it'd support "user defined" "8bit" characters - which probably refers to the 7-pin graphics mode)
- NLQ401 User Manual (German)
- NLQ401 Service Manual (German)
- uPD7811G Datasheet (8bit CPU with 4096 byte ROM, 256 byte RAM, 44 I/O lines)
- uPD78C11A Datasheet (CMOS version of uPD7811, this datasheet version includes some info fragments on MODE0/MODE1 pins)
- NLQ401 ROM Image (this is only the 16K EPROM image, not including the additional 4K ROM which is located inside of the CPU)
The label, saying Centronics Data Computer Corp., Model No. 3101, at the bottom of the NLQ401 printer reveals that the hardware wasn't produced by Schneider themselves. Nearly identical hardware was also distributed by other companies, like the Brother M1009.
Reportedly, the Schneider NLQ 401 is same as Centronics GLP 500 and Brother M1009 (but, see below for extra info concerning missing near-letter quality support on Brother M1009).
The NLQ 401 does also resemble the Commodore MPS-803 (at least externally).
Centronics GLP 500
Commodore printer, apparently from the same manufacturer, and probably containing more or less the same hardware. Known differences are: MPS-803 uses a CBM-style serial port (no centronics port). And control codes and character set in BIOS may differ from the Amstrad version, too. (other picture)
The MPS-803 uses the same 9-pin head as the NLQ401, but reportedly it has only 8-pins installed, more confusingly, the MPS-803 uses only 7-pins for both Text and Graphics printing (producing a similar picture as the older MPS-801/DMP1).
Info from Michael Wessel:
- I was very happy when I could acquire a brand new, very inexpensive 9-pin dot matrix printer for only 200,- DM. The Brother M1009 was a discontinued model. The only difference to the official 'CPC printer' which was sold by Schneider, the NLQ401, was a different case color, different label, and a software Eprom which enabled the NLQ 401 to print in Near Letter Quality which was something the M1009 couldn't do.
The east-german Robotron 6313 consists of different hardware, but it supports a NLQ401 software compatible mode which can be activated via DIP switches.
- http://en.wikipedia.org/wiki/Centronics - wikipedia on Centronics Data Computer Corporation (includes info about their GLP "Great Little Printer" series)