Changes
/* Original serial interface (1985) */ Nothing bad about an external PSU!
=== Original serial interface (1985) ===
Amstrad's first serial interface was one of the original peripherals released for the CPC. It was remarkable (in a bad way) for the necessity for an external, brick-like power supply.
Software was supplied on ROM, mostly comprising utility commands for hobbyists rather than a comms application per se - though there was limited terminal emulation for connecting to the then-popular [[Prestel]] service]. The original, UK version included commands for file transfer entitled |SUCK and |BLOW, which used a proprietary Amstrad format similar to [[XModem]]-1k but, annoyingly, subtly incompatible. These commands were reputedly renamed for the US edition to avoid causing offence.
The French company [[M.E.R.C.I.]] sold a custom version of this interface, replacing the original 8k ROM with an 16k Rom adding a [http://en.wikipedia.org/wiki/Minitel minitel] emulator.
Because of the external power supply and the poor quality of the software, this model failed to establish itself as the "standard" serial interface in the way that (say) the [[DDI-1]] did for disc drives. This allowed other serial interfaces to flourish, such as those sold by [[Cirkit]] and [[KDS]].
=== Pace serial interface (1986) ===
As a result, Amstrad dropped their original design and instead chose to remanufacture a [[PACE]] design. This included significantly improved hardware (a more compact interface thanks to SMD components and no external PSU) and vastly superior software. However, this redesign also reduced the quality of RS232 signalling by using 0V/5V output voltage instead of -12V/12V.
The software was a ROM version of the [[Commstar]] terminal utility from [[HoneySoft]]. This was a user-friendly program with standard [[XModem]] file transfer functions. However, one foolish design decision was the idea of using a 24x80 screen with a single-line status display - though presenting a good user interface, this forced the use of software rather than hardware scrolling, making the interface unusable for terminal emulation at any speed above 2400 baud.
== Alternative software ==
The limitations of the [[Commstar ]] software, and the desire to use more recently developed file transfer protocols (such as [[XModem]]-1k, [[YModem]] and [[ZModem]]) meant that many users chose to use their Amstrad serial interface with third-party software. This included: * [[Ansiterm]] - a fast AMSDOS utility (also known as ANSI.ARC)* [[Charley's Comms ROM]] - sideways ROM capable of 4800 baud terminal emulation* [[ZMP]] - ZModem file transfer under CP/M A vast range of comms software was available for [[CP/M]], including [[Bulletin board|bulletin board]] hosts, offline readers (notably [[CRR]] - CP/M Read and Reply), and many terminals.
== Pictures ==
Image:Amstrad rs232 2.jpg|The original Amstrad serial interface
Image:Amstrad rs232 power1.jpg|The original powersupply that came with the interface
Image:AmstradRS232PSU_Rating.jpg|The original powersupply rating
Image:Amstrad RS232C Box.jpg|Old interface, boxed
Image:Amstrad RS232C Device.jpg|Old interface with PSU
Image:Amstrad RS232C PCB.jpg|Old interface, PCB
</gallery> <gallery caption="Amstrad's original interface 300dpi scans">Image:NoPictureAmstrad_RS232C_Top_EN.gifjpg|Better resolution of PCB Interface Top (with legible part numbers on chipsetEnglish)Image:Amstrad_RS232C_Top_FR.jpg|Interface Top (French)Image:Amstrad_RS232C_PCB_Top.jpg|Interface PCB TopImage:Amstrad_RS232C_PCB_Bottom.jpg|Interface PCB Bottom
</gallery>
== Manuals ==
* [[Media:RS232C Serial Interface (Amsoft UK) Manual.pdf|RS232C Serial Interface (Amsoft UK) Manual]] {{EN}} {{PDF}}
* [[Media:RS232C Interface Serie (Amsoft FR) Manual.pdf|RS232C Interface Serie (Amsoft FR) Manual]] {{FR}} {{PDF}}
* [[Original Amstrad RS232 interface|Manual of the original RS232 by Amstrad (OCR)]]
* [[Media:RS232 (Pace ) Manual... none such scanned yet...pdf|RS232 (Pace) Manual]] {{EN}} {{PDF}}
== Downloads ==
* [[Media:RS232101.ZIP|ROM Image for original version]] - 8K ROM
* [[Media:RS232Mercitel14.rom|ROM Image for Mercitel version]] - 16K ROM
* [[Media:AmstradPaceSerialInterfaceCommstarRomImage.zip|ROM Image for Pace version]] - Commstar 32K ROM (two 16K banks)
* [[Media:PACE232.ZIP|ROM Image for Pace version]] - Commstar 32K ROM
[[Category:Peripherals]][[Category:Network]][[Category:Communication Software]] [[Category:Serial_interfaces]][[Category:Amstrad Products]][[Category:Expansion ROM]]
