VDIP Pinout (set jumper to UART, J3=J4= 2+3)
Pin  1 5V
Pin  6 TXD (UART data output)
Pin  7 Gnd
Pin  8 RXD (UART data input)
Pin  9 RTS (short to CTS)
Pin 10 CTS (short to RTS)
Pin 18 Gnd
Pin 22 !Reset

baud rate 9600bps upon powering up.

every command must end with 0x0D


2017-02-06 Evaluation
1) When VDIP1 is powered up, it will send out the following text
-> "<CR>Ver 03.68VDAPF On-Line:<CR>"

2) When a thumdrive is connected
-> "Device Detected P2<CR>
No Upgrade<CR>
D:\><CR>"

3) When ascii command DIR<CR> is issued.
-> <CR>
SYSTEM~1 DIR<CR>
D:\><CR>



2017-02-07 Short command evaluation (Hex data)

1) Check for presence of a disk 
(when there is no thumbdrive plugged in)
Send    -> 0D
Receive <- "No Disk<CR>"

(when there is thumbdrive plugged in)
Send    -> 0D
Receive <- "D:\><CR>"

2) Switch to short command mode.
Send    -> 10 0D
Receive <- 3E 0D (mean command accepted)

3) Repeat command checking for presence of a disk (in short command mode)
(when there is thumbdrive plugged in)
Send    -> 0D
Receive <- 3E 0D

When thumbdrive is unplugged
Receive <- 44 52 32 0D	"DR2<CR>" 	(slave device removed from port 2)
Receive <- 4E 44 0D	"ND<CR>"	(no disk)

(when there is no thumbdrive plugged in)
Send    -> 0D
Receive <- 4E 44 0D	"ND<CR>"