The files SOLOS13.ASM and SOLOS41.ASM both contain SOLOS version 1.3. When
SOLOS41.ASM is assembled with the HELIOS flag FALSE, it generates the same
code as assembling SOLOS13.ASM.

SOLOS41 is named from the 5204 personality module from which the code was
obtained. This board has four 5204 EPROMs labeled "4.1 S0" through "4.1 S3". 

When using a Helios disk subsystem, EPROM S1 is replaced with a Helios boot
EPROM that adds a new BO (Boot from Helios disk) command in place of the TE
(Terminal mode) command.

SOLOS41.ASM is a reconstruction of the source code with an assembly-time
switch to create either the standard SOLOS 4-1 EPROMs or the SOLOS 4-1
Helios boot EPROMs. The hex files created by this source code matches the
Processor Technology EPROMs exactly in both modes.

The file SOLOS13C.ASM is SOLOS13 modified to fix a glitch with CP/M version
1.4. See the source code for details.