Features Only in the MAX7000S
・JTAG interface ISP (In System Program img)
Function: Rewriting is possible even when the device is mounted on the board
・JTAG BST (Boundary Scan Test)
Internal circuit: (EPM7128S, EPM7160S, EPM7192S, EPM7256S devices only)
・Open drain output setting
・Fast Input Register
・Global output enable: 6
・Global clock pin: 2 (MAX7000 has 1)
・Slew rate control (selectable for low-noise operation mode or high-speed performance operation mode)
 
That's the main difference.
 
For individual detailed differences, please refer to the MAX 7000 Device Handbook at the URL link below.
・page 4 Table 4. MAX 7000 Device Features
・page 9 Figure 3. EPM7032, EPM7064 & EPM7096 Device Macrocell
・page 10 Figure 4. MAX 7000E & MAX 7000S Device Macrocell
Please refer to.
 https://www.altera.com/en_US/pdfs/literature/ds/m7000.pdf