getDebugChar
while ((ch = (getDebugChar () & 0x7f)) != '$');
ch = getDebugChar () & 0x7f;
xmitcsum = hex (getDebugChar () & 0x7f) << 4;
xmitcsum += hex (getDebugChar () & 0x7f);
while ((getDebugChar () & 0x7f) != '+');