The Small Computer Monitor supports a range of hardware and options. These are determined at compile time and are identified by a configuration code. The current configurations are listed below.

Only a few of these have been ported from SCM v1.0 to SCM v1.1

Config.	Description	ROM	RAM
00	Complete custom build
C1	Z80sc, standard ROM SCM, BASIC, CP/M loader Maintained by SCCousins	1 bank of 32k	32k or 64k paged
F1	Z50Bus, standard ROM SCM, BASIC, CP/M loader Maintained by SCCousins	1 bank of 32k	32k or 64k paged
L1	LiNC80 SBC1, standard ROM SCM, BASIC, CP/M loader Maintained by SCCousins and Jon Langseth	2 banks of 16k	48k or 64k paged
R1	RC2014, official image 9 SCM only Maintained by SCCousins	1 bank of 8k	32k no paging
R2	RC2014 SCM and BASIC Maintained by SCCousins	1 bank of 16k	48k no paging
R3	RC2014 SCM, BASIC, CP/M loader Maintained by SCCousins	1 bank of 32k	32k or 64k paged
R4	RC2014, official image 88 SCM, BASIC, CP/M loader Maintained by SCCousins	1 bank of 16k	32k or 64k paged
S1	SC101, standard ROM SCM, BASIC, CP/M loader Maintained by SCCousins	1 bank of 8k	32k or 64k paged
S2	SC114, standard ROM SCM, BASIC, CP/M loader Maintained by SCCousins	1 bank of 32k	32k or 64k paged
S3	SC108, standard ROM SCM, BASIC, CP/M loader Maintained by SCCousins	1 bank of 32k	32k or 64k paged
S4	SC111, Z180 CPU SCM, BASIC, CP/M loader Maintained by SCCousins	1 bank of 32k	32k or 64k paged
S5	SC111+SC119, Z180 system SCM, BASIC, CP/M loader Maintained by SCCousins	512k Z180 MMU	512k Z180 MMU
S6	SC126, Z180 Motherboard SCM, BASIC, CP/M loader Maintained by SCCousins	512k Z180 MMU	512k Z180 MMU
T1	Tom’s SBC revision C SCM, BASIC, CP/M loader Maintained by SCCousins	1 bank of 16k	48k or 84k paged
Z1	Z280RC by Bill Shen Maintained by Bill Shen
Z?	Z80SBC64 by Bill Shen Maintained by Bill Shen

Notes

S4
This configuration is designed as a stepping stone from a working Z80 based RC2014 to a Z180 processor. Simply replace the Z80 CPU with a Z180 CPU and install this version of SCM. All I/O is provided by the existing external hardware (not the Z180) and any required memory management is also provided by existing external hardware.

S5
This configuration is used when a complete Z180 design is required. Z180 internal peripherals, such as serial, are used instead of external ones.

Supported Hardware

The following hardware is specifically supported, and used, by SCM. Other hardware may also exist in the system, but SCM does not provide support or use it. However, software loaded and run from SCM might make use of such hardware.

Config.	Supported hardware
F1	Z80 CPU (eg. Z84C00xx) SIO #1 at 0x80 (eg. Z84C42xx) CTC #1 at 0x88 (eg. Z84C30xx) Bit-bang serial port Digital I/O at 0x52 Compact Flash at 0x10 for loading CP/M
L1	Z80 CPU (eg. Z84C00xx) SIO at 0x00 (eg. Z84C42xx) CTC at 0x08 (eg. Z84C30xx) Digital I/O at 0x30
R1 & R2	Z80 CPU (eg. Z84C00xx) ACIA #1 at 0x80 (eg. 68B50) ACIA #2 at 0x40 (eg. 68B50) SIO #1 at 0x80 (eg. Z84C42xx) Digital I/O at 0x00
R3 & R4	Z80 CPU (eg. Z84C00xx) ACIA #1 at 0x80 (eg. 68B50) ACIA #2 at 0x40 (eg. 68B50) SIO #1 at 0x80 (eg. Z84C42xx) Digital I/O at 0x00 Compact Flash at 0x10 for loading CP/M
S2	Z80 CPU (eg. Z84C00xx) ACIA #1 at 0x80 (eg. 68B50) ACIA #2 at 0x40 (eg. 68B50) SIO #1 at 0x80 (eg. Z84C42xx) Bit-bang serial port (as SC114) Digital I/O at 0x00 Compact Flash at 0x10 for loading CP/M
S3	Z80 CPU (eg. Z84C00xx) ACIA #1 at 0x80 (eg. 68B50) ACIA #2 at 0x40 (eg. 68B50) SIO #1 at 0x80 (eg. Z84C42xx) CTC #1 at 0x88 (eg. Z84C30xx) Digital I/O at 0x00 Compact Flash at 0x10 for loading CP/M
S4	Z180 CPU (eg. Z8S180xx) ACIA #1 at 0x80 (eg. 68B50) ACIA #2 at 0x40 (eg. 68B50) SIO #1 at 0x80 (eg. Z84C42xx) CTC #1 at 0x88 (eg. Z84C30xx) Digital I/O at 0x00 Compact Flash at 0x10 for loading CP/M
S5	Z180 CPU (eg. Z8S180xx) Z180’s asynchronous serial ports Z180’s internal timer (for idle events) Digital I/O at 0x00 Compact Flash at 0x10 for loading CP/M
S6	Z180 CPU (eg. Z8S180xx) Z180’s asynchronous serial ports Z180’s internal timer (for idle events) Digital I/O at 0x00 Compact Flash at 0x10 for loading CP/M Status / self-test LEDs at 0x0D

Hardware Identification Codes

These are hardware identifiers used within SCM and returned as part of the SCM version details.

Config.	Description	ID	Name	Hardware
0#	Custom	0	<custom>	—
C#	Z80sc	13	Z80sc	SC121
F#	Z50Bus	14	Z50Bus	SC118
L#	LiNC80	5	LiNC80	SBC1
R#	RC2014	3	RC2014	Z80
S1	SC_S1	4	SC101	SC101
S2	SC_S2	8	SC114	SC114
S3	SC_S3	10	SC3	SC108
S4	SC_S4	11	Z180	SC111
S5	SC_S5	12	Z180_RC	SC111+119
S6	SC_S6	12	SC126	SC126
T1	TomsSBC	6	TomsSBC	SBC vC
W#	Simulated	1	Simulated	—
Z1	Z280RC	7	Z280RC	Z280RC
Z2	Z80SBC64	9	Z80SBC64	Z80SBC64
—	SCDevKit01	2	SCDevKit01	—

Hardware Flags Summary

Hardware identified by SCM is indicated by the flags described below. These flags are returned as part of the SCM version details.

SCM Config.	bit 7	bit 6	bit 5	bit 4	bit 3	bit 2	bit 1	bit 0
Z80sc C#	Z180 serial	CTC 0x8C	SIO 0x84	CTC 0x88	Bit- bang	ACIA 0x40	SIO 0x80	ACIA 0x80
Z50Bus F#	n/a	CTC 0x8C	SIO 0x84	CTC 0x88	Bit- bang	n/a	SIO 0x80	n/a
LiNC80 L#	n/a	n/a	n/a	n/a	n/a	n/a	n/a	SIO 1 0x00
RC2014 R#	Z180 serial	CTC 0x8C	SIO 0x84	CTC 0x88	Bit- bang	ACIA 0x40	SIO 0x80	ACIA 0x80
RC2014 S#	Z180 serial	CTC 0x8C	SIO 0x84	CTC 0x88	Bit- band	ACIA 0x40	SIO 0x80	ACIA 0x80
TomsSBC T1	n/a	n/a	n/a	n/a	n/a	n/a	n/a	SIO 1 0x00

Hardware Flags for RC2014 Systems

Hardware flags for other configurations of SCM may indicate different hardware.

Flag bit	Hardware for SCM configurations R# and S#
Bit 0	ACIA #1 at 0x80
Bit 1	SIO #1 at 0x80
Bit 2	ACIA #2 at 0x40
Bit 3	Bit-bang serial, or SIO #1 in RC2014 addressing compatibility mode
Bit 4	CTC #1 at 0x88
Bit 5	SIO #2 at 0x84
Bit 6	CTC #2 at 0x8C
Bit 7	Z180’s internal serial ports

Hardware flag for each configuration are detailed below.

SCM Config.	bit 7	bit 6	bit 5	bit 4	bit 3	bit 2	bit 1	bit 0
RC2014 R1 to R4	0	0	0	0	0	ACIA 0x40	SIO 0x80	ACIA 0x80
RC2014 S2	0	0	0	0	Bit- bang	ACIA 0x40	SIO 0x80	ACIA 0x80
RC2014 S3	0	0	0	CTC 0x88	SIO 1 mode	ACIA 0x40	SIO 0x80	ACIA 0x80
RC2014 S4	0	0	0	CTC 0x88	SIO 1 mode	ACIA 0x40	SIO 0x80	ACIA 0x80
RC2014 S5	Z180 serial	0	0	0	0	0	0	0
RC80 S6	Z180 serial	0	0	0	0	0	0	0