Slide Show.
Standard version.
VGA Exits via the bottom where RGB would exit on a
standard Color Computer 3
A 3-D printed mounting block is attached to the origional case
with glue.
Serial Cable is taken inside the case to attach to a strain
relief directly on the motherboard and exits via the former RF
output port.
Version with Backside Coutout for High Speed DB-9 Serial
Port.
This version involves modifying the case or getting a
clone case top 3-D printed.
Tx
t
If the ROM select set to 3 with no cartrige pluged in the
CoCo 4 boots to Extended Color Basic 2.1
If the ROM select set to 4 the CoCo 4 boots to either:
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- 00 - Basic 4,
- 01 - Basic4 Drive Wire Auto Boot
- 10 - Start Menu
- 11 - Custom ROM (Which user must supply)
If The Start Menu Option is not selected them hold down S on power up.
Holding B or D on power up starts Basic or Drive Wire Boot respectively.
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There should be at least 1 Meg of memory.
Preferably built in.
There also should be at least 8K of battery backed static memory to store settings and keyboard macros.
Compareing the CoCo4+ with the CoCo 4 we see that the memory has been upgraded to 4Meg.
This requires an alternative MMU mode where there are 4 8K banks for the low 32K and 2 16K banks for the high 32K.
The alternate mode would require special software so is only used with special software that is triggered by an interupt.
The main difference between the CoCo4+ and the CoCo4++ is that there is an aditional virtual 6309 and an additional 512K RAM.
The origional CPU we call CPU#1 and the additional CPU we call CPU#2.
CPU#2 uses standard MMU mode only so there is access a maximum of 2Meg.
The aditional three 512K blocks available to CPU#2 are assigned at POWER ON STARTUP.
CPU#2 has exclusive access to the additional 512K "Superblock G".
It also has shared access to 3 Other Superblocks by default these are:
"512K-Superblock F" to allow for 1M RAM if not used by CPU#1
"256K-Superblock M" for Shared Buffer Access.
"256K-Superblock T" for virtual casettes.
and the Top 512K of "Superblock U" for 2 160K volatile drives and the shared 160K "Drive 8".
CPU#1 has access to the non-volatile 160K drive U0: and a virtual 720K OS9 /ud1.