Changes

[[Amstrad]] released == The two [[RS232]] interfaces, both using the same input/output addresses - and, ultimately, therefore establishing the standard for serial interfaces - but with significantly different hardware.Amstrad Interfaces ==

== Original [[Amstrad]] released two [[RS232]] interfaces, both using the same input/output addresses - and, ultimately, therefore establishing the standard for serial interface ==interfaces.

The main difference between the interfaces is that they contain different firmware, and the older one required an external power supply. === 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.

=== Pace serial interface (1986) ===

As a result, Amstrad dropped their original design and instead chose to remanufacture a [[PacePACE]] 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 Pace's the [[Commstar]] terminal utility, from [[CommstarHoneySoft]]. 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. The Amstrad/Pace version was announced on [[:File:ACU8612006.jpg|Amstrad Computer User, Dec 1986, page 6]]. A review occured in Amstrad Computer User, April 1987, pages 46 and 47.

Here are the I/O Ports (same for original and Pace version):  FADCh Amstrad RS323 RS232 [[Z80-DART/Z80-SIO chip|Z8470 (Z80 DART) ]] Channel A Data (R/W) FADDh Amstrad RS323 RS232 [[Z80-DART/Z80-SIO chip|Z8470 (Z80 DART) ]] Channel A Control/Status (R/W) FADEh Amstrad RS323 RS232 [[Z80-DART/Z80-SIO chip|Z8470 (Z80 DART) ]] Channel B Data (R/W) FADFh Amstrad RS323 RS232 [[Z80-DART/Z80-SIO chip|Z8470 (Z80 DART) ]] Channel B Control/Status (R/W) FBDCh Amstrad RS323 RS232 [[8253 chip|8253]] Baudrate Timer 0 Channel A TX Clock (R/W) FBDDh Amstrad RS323 RS232 [[8253 chip|8253]] Baudrate Timer 1 Channel A RX Clock (R/W) FBDEh Amstrad RS323 RS232 [[8253 chip|8253]] Baudrate Timer 2 Channel B RX/TX Clock (R/W) FBDFh Amstrad RS323 RS232 [[8253 chip|8253 ]] Baudrate Timer 0-2 Control Registers (W)

Below is information about the 8250 UART * [[Z80-DART/Z80-SIO chip. As far as known, the Amstrad Serial Interface does NOT use that ]]* [[8253 chip. No idea why that information is here...?]]

Like Although the original interface, the Pace design used an 8250 [[UART]] chip, which was reliable up to 9600 baud Z80-DART (and could sometimes function at faster speeds. The possibility has been discussed of replacing this with a pinZ80-compatible 16550 and gaining even faster transfer speedsSIO) support two channels, but this is not believed most or all existing CPC interfaces seem to have been testeduse only one channel.

[http:== CP/M == The I/en.wikipediaO ports are directly supported under CP/M (without needing additional drivers).orgLike many CP/wiki/8250_UART Linkt to Article on Wikipedia about M functions, the 8250 UART used functions are located in the interface]AMSDOS ROM (not on the CP/M disc). These functions are using hardcoded RAM addresses, which conflict with the BASIC memory map, so they can be used only under CP/M, not under BASIC.

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:

A vast range of comms software was available for [[CP/M]]<gallery caption="Amstrad's older original serial interface">Image:amstrad RS232C.jpg|The original Amstrad serial interfaceImage:Amstrad rs232 1.jpg|The original Amstrad serial interfaceImage:Amstrad rs232 2.jpg|The original Amstrad serial interfaceImage:Amstrad rs232 power1.jpg|The original powersupply that came with the interfaceImage:AmstradRS232PSU_Rating.jpg|The original powersupply ratingImage:Amstrad RS232C Box.jpg|Old interface, including [[Bulletin boardboxedImage:Amstrad RS232C Device.jpg|bulletin board]] hostsOld interface with PSUImage:Amstrad RS232C PCB.jpg|Old interface, offline readers (notably [[CRR]] - CPPCB</M Read and Reply), and many terminals.gallery>

<gallery caption== Technical specs =="Amstrad's original interface 300dpi scans">Image:Amstrad_RS232C_Top_EN.jpg|Interface Top (English)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>

This [http<gallery caption="Amstrad's newer Pace serial interface">File:Amstrad RS232.jpg|Newer Amstrad//wwwPace InterfaceFile:Amstrad_RS232_Pace_Interface.systemedjpg|Pace InterfaceFile:Amstrad_RS232_Pace_PCB_Top.net/pcw/cps8256jpg|PCB TopFile:Amstrad_RS232_Pace_PCB_Bottom.html webpage about the CPS8256] jpg|PCB BottomFile:ACU8701002.jpg|Advert (the Amstrad serial interface for the PCWACU, January 1987) also includes some useful CPC information (and may be worth converting in due course).</gallery>

== Manual Schematic and More (CPS8256) ==

[[Original Amstrad RS232 interface|Manual of Below shows schematic and pictures for the CPS8256 Serial Interface (for the original RS232 by Amstrad PCW, aka Schneider Joyce), ie. it is ''not'' really CPC hardware, however, the CPC interface should use a similar design (OCRthe major difference is probably that the CPC version contains a BIOS ROM, but no Centronics port). Credits: The gif and jpg's are from [http://www.z80.eu/cps8256.html www.z80.eu]].

<gallery caption="CPS8256">File:Cps8256-circuit.gif|SchematicFile:Cps8256-case-lower.jpg|Case lower sideFile:Cps8256-case-upper.jpg|Case upper sideFile:Cps8256-pcb-component-side.jpg|Component sideFile:Cps8256-pcb-component-noadd2.jpg|Without componentsFile:Cps8256-pcb-layer-side.jpg|Solder sideFile:Cps8256-additional-pcb-side.jpg|Voltage converterFile:Cps8256-additional-pcb-upper.jpg|Voltage converter</gallery> = Pictures = Reviews ==  <gallery>image:Amstrad_Computer_User8509025.jpg|Review in [[Amstrad Computer User]]image:Amstrad_Computer_User8509026.jpg|image:Amstrad_Computer_User8509027.jpg|image:Amstrad_Computer_User8509028.jpg|</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.pdf|RS232 (Pace) Manual]] {{EN}} {{PDF}} == Downloads ==

<gallery caption="Amstrad serial interface">Image* [[Media:amstrad RS232CRS232101.jpgZIP|The ROM Image for original, flawed Amstrad serial interfaceversion]] - 8K ROMImage* [[Media:Amstrad rs232 1RS232Mercitel14.jpgrom|The original, flawed Amstrad serial interfaceROM Image for Mercitel version]] - 16K ROMImage* [[Media:Amstrad rs232 2AmstradPaceSerialInterfaceCommstarRomImage.jpgzip|The original, flawed Amstrad serial interfaceROM Image for Pace version]] - Commstar 32K ROM (two 16K banks)Image* [[Media:Amstrad rs232 power1PACE232.jpgZIP|The original powersupply that came with the interface</gallery>ROM Image for Pace version]] - Commstar 32K ROM

[[Category:HardwarePeripherals]] [[Category:PeripheralsNetwork]][[Category:Communication Software]] [[Category:Serial_interfaces]][[Category:Amstrad Products]][[Category:Expansion ROM]]