Differences

This shows you the differences between two versions of the page.

--- boards:ecb:2s1p:start [2021/04/22 18:00] – Initial import from Wayback Machine
+++ boards:ecb:2s1p:start [2026/06/15 12:15] (current) – external edit 127.0.0.1
@@ Line 1: / Line 1: @@
 /* Imported from Wayback Machine
    Original URL : https://www.retrobrewcomputers.org/doku.php?id=boards:ecb:2s1p:start
-   Snapshot date: 2021-04-22
+   Snapshot date: 2025-08-16
    Generator    : wayback-archiver
 */
@@ Line 26: / Line 26: @@
 The resistor arrays (RN501, RN502) that are part of the RC damper circuit for the parallel port are //isolated// resistors, not the more common bussed resistor arrays that most builders have in stock. They are also an uncommon value (27 ohms) for your typical RetroBrew build. The schematic shows this difference, but if you go straight by the BOM, that difference isn't clear.
+==== Jumpers ====
+AT/EPP: this jumper controls the parallel port mode supported by the 16C552. For use with DOS, I leave it in the most-compatible AT mode.
+DCE/DTE: these jumpers (one for each port) controls whether the port acts as a terminal (DTE) or a modem (DCE); effectively a chip-controlled null-modem switch.
+RTS/DTR: these jumpers select which handshaking signal appears at the TTL-level 6-pin header.
+INT/NMI: these jumpers control which interupt line the respective port is mapped to; unused with the current drivers, so leave open.
+BRD_SEL: this jumper controls which ECB port range the board is assigned to. For the SBC-188, this is offset by 0x400 in software (so, Cx = $4Cx) due to how off-board ports are mapped by the SBC-188 card.
 ===== Errata =====
-None in version 1.0-001 (the first production run).
+Version 1.0-001: A small silkscreen error was found (11/6/2022) – the COM1 and LPT designators above P302 and P303 should be swapped. There is no impact to operations from this error.
 ===== Software =====
@@ Line 45: / Line 57: @@
 |[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=boards:ecb:2s1p:ecb_driver_rel01.zip|ECB 2S1P_driver_rel01.zip]]   |39Kb |2020-01-17|
-\\
+===== Software =====
+The UAR/T used is a derivative of the Intel 8251 UAR/T so most basic code will run without significant modification. To use with MS-DOS on the SBC-188, TSR (terminate and stay resident) drivers are required to provide replacement BIOS functions (none of the BIOSes, including the latest BIOS-050, do not have any code to support the board). Additionally, most DOS programs assume that the serial and parallel ports live at specific I/O port addresses and are interrupt-capable. On versions of the SBC-188 prior to version 3, the interrupt system doesn't conveniently allow for interrupt-driven serial ports such as the 2S1P, so the 2S1P has to be run in “polled” mode. It's expected that version 3 of the SBC-188 will have a usable/trappable interrupt that can be connected to the 2S1P to allow for most software to work; the I/O port and interrupt selection allocation will still be an issue but that's easier to deal with.
+The software should be considered “beta” quality.
+===== Resources =====
+^Filename                                                                                                                        ^Size ^Updated   ^
+|[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=boards:ecb:2s1p:ecb_2s1p-1.0-001_sch.pdf|ECB 2S1P-1.0-001_sch.pdf]]|724Kb|2019-12-27|
+|[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=boards:ecb:2s1p:ecb_2s1p-1.0-001_pcb.pdf|ECB 2S1P-1.0-001_pcb.pdf]]|500Kb|2019-12-27|
+|[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=boards:ecb:2s1p:ecb_2s1p-1.0-001.zip|ECB 2S1P-1.0-001_design.zip]] |2.1Mb|2020-01-12|
+|[[https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=boards:ecb:2s1p:ecb_driver_rel01.zip|ECB 2S1P_driver_rel01.zip]]   |39Kb |2020-01-17|